RMU VLabNet 7 - Border Gateway Protocol

RMU VLabNet 7.4-BGP - Virtual Laboratory Networking Exercises

INFS6230 and INFS6760 – RMU C&IS

Command Summary and Examples

BGP (Border Gateway Protocol) Please see: http://www.quagga.net/docs/docs-multi/BGP.html#BGP Quagga BGP (including configuration) examples can be found at the Quagga Wiki: http://wiki.quagga.net/index.php/Main/CfEx

See Tanenbaum, §5.6.5 BGP – The Exterior Gateway Routing Protocol, pp. 459-461. Please note examples of routing constraint implementation of policies, p. 460. The Autonomous System (AS) concept; see Tanenbaum/Wetherall 5e, pp. 432, 437, 472-476, 474.
Rationale (why include BGP in this course: BGP is in use at any enterprise wanting to truly multi-home to the Internet with two providers. This includes most of the Fortune 500, most large educational institutions, most major "Internet" or e-commerce companies, and of course all the various service providers. In addition, many enterprises with multiple wide-area network sites also now purchase MPLS-based L3 IP VPN services from carriers. In these deployments, there is a routing protocol running between the enterprise customer's equipment (CE) and the provider's router (PE). This protocol is often BGP because of the scale and control it offers. From Draft-ietf-l3vpn-rfc2547 (“BGP/MPLS IP VPNs”): "BGP is explicitly designed for just this function: passing routing information between systems run by different administrations." See also Juniper MPLS VPN, esp. Figure 2 on the 4^th page; and Rekhter and Rosen, "Carrying Label Information in BGP4", RFC 3107, May 2001. For MPLS (Multi-Protocol Label Switching) see Tanenbaum/Wetherall 5e, pp. 357, 360, 471-474; for VPN (Virtual Private Network) see Tanenbaum/Wetherall 5e, pp. 4, 26, 431, 821-822.
To edit /etc/quagga/daemons so that zebra and bgpd will be enabled as needed on reboot or restart.

Edit command:

vi /etc/quagga/daemons

zebra=yes

bgpd=yes

ospfd=yes

ospf6d=no

ripd=yes

ripngd=no

isisd=no

If OSPF and RIP are running as well (recommended for the sake of routing analytics learning), there will also be a yes for ospfd and ripd in the daemons file (as shown).

Design of INFS6230 activities: Groups: five teams of students (about 5 per team) will form Autonomous Systems (ASs). Each VM will be regarded as a (border) router. Thus VM102 is BR102 for these exercises. iBGP connections for students’ routers within team: meshed - every node connected to every other node; exchange of external reachability information within an Autonomous System (AS). eBGP connections with nodes in other Autonomous Systems (ASs); exchange of reachability information between ASs. Learn transit routing and peering between different parties that make up tier 1 of the Internet (learn how the Internet works)
Regarding AS numbers (ASNs) 64501-64505, please see IANA “private AS numbers” : http://www.iana.org/assignments/as-numbers: 64496-64511 according to RFC 5398: http://tools.ietf.org/html/rfc5398. Designated for private use (Allocated to the IANA).
Check configuration file, especially /etc/quagga/bgpd.conf. See examples below (where in view of their role in each AS, routers are designated BRs (Border Routers) and eBGP Peering Diagrams BGP-11 through BGP-11c, mesh iBGP Peering in an Autonomous System. For example in a given Autonomous System 64501 there will be internal BGP (iBGP) peering from, say, BR102 to the four other VMs in the AS: 103, 104, 105, and 106 in the same AS, and eBGP peering to R107 in AS 64502. There will be internal mesh BGP (iBGP) peering from, say, BR103 to the four other Routers in the AS: BR102, BR104, BR105, and BR106, in the same AS, and eBGP peering from BR106 to BR116 in AS 64503 and from four of AS 64501’s BRs to a BR in AS 64505 or AS 64502. Note that eBGP peerings must be specified in the configuration file to obtain the correct configuration. Unlike the case with RIP and OSPF, which used interface eth1 addresses for routing, for BGP we will be using eth0 addresses.
After editing files and before retarting/starting, halt all the zebra, ripd, and ospfd processes you already have running. Zebra will not read the new version of your daemons file until it is halted and restarted. The restart/start processes.
Make sure zebra has been (re-)started first. If not,
to start zebra: /usr/lib/quagga/zebra –d (if running RIP and/or OSPF as well for the sake of routing analytics: Routing Analytics, start them in order, zebra before RIP before OSPF; then BGP.)
To start BGP: /usr/lib/quagga/bgpd -d
Access BGP router: telnet localhost 2605; enter password, use enable to gain command mode
If needed, to shut BGP down: kill `cat /var/run/quagga/bgpd.pid` [Or look up PID nnnn using ps –A and kill nnnn.]
If needed, to restart quagga: /etc/init.d/quagga restart
Verification, observe established port 179 TCP connection using netstat -an:

tcp 0 0 x.y.z.125:179 x.y.z.107:4336 ESTABLISHED

To check for packets on interface Ethernet 0, use: tcpdump -i eth0 port 179 [best]

or tcpdump -i eth0 port not ssh

or tcpdump -i eth0 proto tcp

Once your BGP router is correctly configured, please leave your router running (except for brief experiments or to correct your configuration and then restart) until the date given in class to shut it down. Please recall the resulting BGP routing responses online to the collective work of the entire class are important to each member of the class as everyone completes BGP documentation.

Figure 3-11: (BGP Autonomous Systems with Next-Hop Routing Model; Fall 2011)

Figure 3-11b: (BGP Border Routers in Autonomous Systems; Fall 2011)

Figure 3-11c: (BGP Example K₅ Mesh iBGP and eBGP Peerings using AS 64502; Fall 2011)

If needed, see the BGP Troubleshooting page.

OPTIONAL – Autonomous System groups completing configuration quickly may opt to configure route reflection to improve scalability. See VLabNet 7.4-BGP_RR

Please see the /etc/quagga/bgpd.conf file for VM 1mm in AS 64502:

Please note notation here: <iR0> is you. Your (mesh) iBGP peerings are to <iR1>, <iR2> and <iR3>. Your external peering is to <eR1>. Some of you may have a second eBGP peering to <eR2>. remote-as means “(in) remote autonomous system.” AS number 6450<n> means your autonomous system (AS); AS number 6450r means remote AS.

Edit command:

vi /etc/quagga/bgpd.conf

! Configuration file model for VM 1mm in AS 6450<n>

! INFS6230 Fall 2010 RMU C&IS

hostname bgpd

password zebra

enable password #####

! <iR0> = substitute your own vm/router number in your iBGP list

router bgp 6450<n> <your own autonomous system number>

bgp router-id 10.10.10.<iR0>

network 10.10.<iR0>.0/29

! internal mesh – iBGP – same ASN – <iR1>-<iR4> = substitute internal peer vm numbers

! (from your iBGP neighbor list) x.y.z. = our usual first 3 octets

neighbor x.y.z.<iR1> remote-as 6450<n>

neighbor x.y.z.<iR2> remote-as 6450<n>

neighbor x.y.z.<iR3> remote-as 6450<n>

neighbor x.y.z.<iR4> remote-as 6450<n>

! external peering – eBGP – other AS – <eR1> = external peer vm number

! (from your eBGP neighbor list)

! prefix-list - <eR1> = substitute external peer vm/router (from your eBGP neighbor list)

neighbor x.y.z.<eR1> remote-as 6450<r>

neighbor x.y.z.<eR1> prefix-list allowed-in in

ip prefix-list allowed-in seq 5 deny 10.10.<eR1>.0/29

ip prefix-list allowed-in seq 10 permit any

! logging

log syslog

log file /var/log/quagga/bgpd.log

log stdout

line vty

About the neighbor statements in any configuration and the iBGP/eBGP distinction:

neighbor x.y.z.105 remote-as 64502 (same AS; therefore iBGP)

neighbor x.y.z.106 remote-as 64502 (same AS; therefore iBGP)

neighbor x.y.z.108 remote-as 64502 (same AS; therefore iBGP)

neighbor x.y.z.101 remote-as 64501 (different AS; therefore eBGP)

neighbor x.y.z.123 remote-as 64504 (different AS; therefore eBGP)

Fill-in version. Using the guide above, fill in the correct AS numbers and IP and CIDR network addresses:

! Configuration file model (fill-in) for VM 1mm in AS 6450<n>

! INFS6230 Fall 2010 RMU C&IS

hostname bgpd

password zebra

enable password #####

! <substitute your own vm/router number in your iBGP list

! <your own autonomous system number>

router bgp 6450<n>

bgp router-id 10.10.10.____

network 10.10.____.0/29

! internal mesh – iBGP – same AS as yours = substitute internal peer vm numbers

! (from your iBGP neighbor list) x.y.z. = our usual first 3 octets

neighbor x.y.z.____ remote-as 6450__

! external peer vm/router (from your eBGP neighbor list) – different AS from yours

neighbor x.y.z.____ remote-as 6450__

neighbor x.y.z.____ prefix-list allowed-in in

ip prefix-list allowed-in seq 5 deny 10.10.____.0/29

ip prefix-list allowed-in seq 10 permit any

! logging

log syslog

log file /var/log/quagga/bgpd.log

log stdout

line vty

Please note that prefix list allowed-in in identifies the name of the prefix-list as allowed-in and as inbound with regard to VM 121. The sequence numbers order the statements in the prefix list.

Interactive configuration at the config-router prompt (telnet localhost 2605), example from VM 121 in AS 64504:

Password: zebra

bgpd> enable

Password: #####

bgpd# config t [Note Prompt changes from bgpd> to bgpd#]

bgpd(config)#

bgpd(config)# router bgp 6450<n> çuse your AS-number

BGP is already running; AS is 6450<n> Confirmation

bgpd(config-router)#

bgpd(config-router)# bgp log-neighbor-changes

bgpd(config-router)# redistribute connected

bgpd(config-router)# bgp network import-check

bgpd(config-router)# quit

bgpd(config)# quit

bgpd# show ip bgp <options> çyou can enter show ip bgp commands here, see examples belowê

bgpd# quit

By using the ? option in the state, you can see what options you have:

bgpd(config-router)#

address-family Enter Address Family command mode

aggregate-address Configure BGP aggregate entries

bgp BGP specific commands

distance Define an administrative distance

end End current mode and change to enable mode.

exit Exit current mode and down to previous mode

help Description of the interactive help system

ipv6 IPv6 information

list Print command list

neighbor Specify neighbor router

network Specify a network to announce via BGP

no Negate a command or set its defaults

quit Exit current mode and down to previous mode

redistribute Redistribute information from another routing protocol

show Show running system information

timers Adjust routing timers

write Write running configuration to memory, network, or

terminal

bgpd(config-router)# neighbor

A.B.C.D Neighbor address

X:X::X:X IPv6 address

WORD Neighbor tag

By using the ? option after the show ip bgp entry, you can see what options you have:

A.B.C.D Network in the BGP routing table to display

A.B.C.D/M IP prefix <network>/<length>, e.g., 35.0.0.0/8

attribute-info List all bgp attribute information

cidr-only Display only routes with non-natural netmasks

community Display routes matching the communities

community-info List all bgp community information

community-list Display routes matching the community-list

dampened-paths Display paths suppressed due to dampening

filter-list Display routes conforming to the filter-list

flap-statistics Display flap statistics of routes

ipv4 Address family

neighbors Detailed information on TCP and BGP neighbor connections

paths Path information

prefix-list Display routes conforming to the prefix-list

regexp Display routes matching the AS path regular expression

route-map Display routes matching the route-map

rsclient Information about Route Server Client

scan BGP scan status

summary Summary of BGP neighbor status

view BGP view

vpnv4 Display VPNv4 NLRI specific information

<cr>

Error Message examples:

Example of error message if your enter incorrect AS number (like 64504 when AS number is 64503):

bgpd(config)# router bgp 64504

BGP is already running; AS is 64503

BGP router reports:

bgpd# show ip bgp

BGP table version is 0, local router ID is x.y.z.125

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

r RIB-failure, S Stale, R Removed

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*> 10.10.105.0/29 x.y.z.105 0 64502 i

*> 10.10.107.0/29 x.y.z.107 0 0 64502 i

*> 10.10.125.0/29 0.0.0.0 0 32768 i

Total number of prefixes 3

bgpd# show ip bgp summary

BGP router identifier 10.10.10.103, local AS number 64503

RIB entries 33, using 2112 bytes of memory

Peers 4, using 10048 bytes of memory

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd

x.y.z.101 4 64503 52120 53003 0 0 0 05w1d04h 9

x.y.z.102 4 64503 52328 52312 0 0 0 01w5d03h 7

x.y.z.104 4 64503 52316 52312 0 0 0 04w1d04h 3

x.y.z.110 4 64505 52128 52308 0 0 0 04w1d04h 10

Please note next-hop eBGP path listings from this command in the BGP router (in AS 64504):

bgpd# show ip bgp prefix-list allowed-in

BGP table version is 0, local router ID is 10.0.0.109

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

r RIB-failure, S Stale, R Removed

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*> 10.10.10.96/27 0.0.0.0 1 32768 ?

* x.y.z.123 0 64504 ?

*> 10.10.102.0/29 x.y.z.102 0 64504 64502 64501 i

*> 10.10.103.0/29 x.y.z.103 0 64504 64502 64501 i

*> 10.10.106.0/29 x.y.z.106 0 64504 64502 i

*> 10.10.107.0/29 x.y.z.107 0 64504 64502 i

* 10.10.109.0/29 0.0.0.0 1 32768 ?

*> 0.0.0.0 1 32768 i

*> 10.10.116.0/29 x.y.z.116 0 64504 i

*> 10.10.123.0/29 x.y.z.123 0 64504 i

*> x.y.z.96/27 0.0.0.0 1 32768 ?

* x.y.z.123 0 64504 ?

Total number of prefixes 9

bgpd# show ip bgp cidr-only

BGP table version is 0, local router ID is 10.10.10.123

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

r RIB-failure, S Stale, R Removed

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*> 10.10.10.96/27 0.0.0.0 1 32768 ?

*>i10.10.116.0/29 x.y.z.116 0 100 0 i

*>i10.10.117.0/29 x.y.z.117 0 100 0 i

* 10.10.123.0/29 0.0.0.0 1 32768 ?

*> 0.0.0.0 1 32768 i

*> x.y.z.96/27 0.0.0.0 1 32768 ?

Total number of prefixes 5

bgpd# show ip bgp ipv4 unicast

BGP table version is 0, local router ID is x.y.z.125

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

r RIB-failure, S Stale, R Removed

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*>i10.10.10.96/27 x.y.z.117 1 100 0 ?

* x.y.z.101 0 64502 64501 ?

* x.y.z.113 0 64504 ?

* i10.10.10.96/29 x.y.z.103 100 0 64501 i

*>i x.y.z.103 0 100 0 64501 i

* x.y.z.101 0 64502 64501 i

* i10.10.101.0/29 x.y.z.101 100 0 64501 i

*>i x.y.z.101 100 0 64501 i

* x.y.z.101 0 64502 64501 i

* i10.10.102.0/29 x.y.z.102 100 0 64501 i

*>i x.y.z.102 100 0 64501 i

* x.y.z.101 0 64502 64501 i

*>i10.10.103.0/29 x.y.z.103 100 0 64501 ?

* x.y.z.101 0 64502 64501 ?

*>i10.10.104.0/29 x.y.z.104 100 0 64501 i

* x.y.z.101 0 64502 64501 i

* i10.10.107.0/29 x.y.z.107 100 0 64501 64502 i

*>i x.y.z.107 100 0 64501 64502 i

*> 10.10.108.0/29 x.y.z.108 0 64502 i

*> 10.10.109.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.110.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.111.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.112.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.113.0/29 x.y.z.113 0 64504 i

*> 10.10.115.0/29 x.y.z.115 0 64504 i

*> 10.10.116.0/29 x.y.z.116 0 64504 i

*>i10.10.117.0/29 x.y.z.117 0 100 0 i

*>i10.10.118.0/29 x.y.z.118 0 100 0 i

*> 10.10.125.0/29 0.0.0.0 0 32768 i

*>ix.y.z.96/27 x.y.z.117 1 100 0 ?

* x.y.z.101 0 64502 64501 ?

* x.y.z.113 0 64504 ?

Total number of prefixes 19

bgpd# show ip bgp prefix-list allowed-in

BGP table version is 0, local router ID is x.y.z.125

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

r RIB-failure, S Stale, R Removed

Origin codes: i - IGP, e - EGP, ? - incomplete

Network Next Hop Metric LocPrf Weight Path

*>i10.10.10.96/27 x.y.z.117 1 100 0 ?

* x.y.z.101 0 64502 64501 ?

* x.y.z.113 0 64504 ?

* i10.10.10.96/29 x.y.z.103 100 0 64501 i

*>i x.y.z.103 0 100 0 64501 i

* x.y.z.101 0 64502 64501 i

* i10.10.101.0/29 x.y.z.101 100 0 64501 i

*>i x.y.z.101 100 0 64501 i

* x.y.z.101 0 64502 64501 i

* i10.10.102.0/29 x.y.z.102 100 0 64501 i

*>i x.y.z.102 100 0 64501 i

* x.y.z.101 0 64502 64501 i

*>i10.10.103.0/29 x.y.z.103 100 0 64501 ?

* x.y.z.101 0 64502 64501 ?

*>i10.10.104.0/29 x.y.z.104 100 0 64501 i

* x.y.z.101 0 64502 64501 i

*> 10.10.108.0/29 x.y.z.108 0 64502 i

*> 10.10.109.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.110.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.111.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.112.0/29 x.y.z.109 0 64504 64503 i

*> 10.10.113.0/29 x.y.z.113 0 64504 i

*> 10.10.115.0/29 x.y.z.115 0 64504 i

*> 10.10.116.0/29 x.y.z.116 0 64504 i

*>i10.10.117.0/29 x.y.z.117 0 100 0 i

*>i10.10.118.0/29 x.y.z.118 0 100 0 i

*> 10.10.125.0/29 0.0.0.0 0 32768 i

*>ix.y.z.96/27 x.y.z.117 1 100 0 ?

* x.y.z.101 0 64502 64501 ?

* x.y.z.113 0 64504 ?

Total number of prefixes 18

bgpd# show ip bgp neighbors

BGP neighbor is x.y.z.101, remote AS 64501, local AS 64502, external link

BGP version 4, remote router ID 10.10.10.101

BGP state = Established, up for 00:03:19

Last read 00:00:19, hold time is 180, keepalive interval is 60 seconds

Neighbor capabilities:

Route refresh: advertised and received(old & new)

Address family IPv4 Unicast: advertised and received

Message statistics:

Inq depth is 0

Outq depth is 0

Sent Rcvd

Opens: 1 1

Notifications: 0 0

Updates: 11 5

Keepalives: 5 4

Route Refresh: 0 0

Capability: 0 0

Total: 17 10

Minimum time between advertisement runs is 30 seconds

For address family: IPv4 Unicast

Community attribute sent to this neighbor(both)

Inbound path policy configured

Incoming update prefix filter list is *allowed-in

8 accepted prefixes

Connections established 1; dropped 0

Last reset never

Local host: x.y.z.107, Local port: 2480

Foreign host: x.y.z.101, Foreign port: 179

Nexthop: x.y.z.107

Nexthop global: ::

Nexthop local: ::

BGP connection: non shared network

Read thread: on Write thread: off

BGP neighbor is x.y.z.105, remote AS 64502, local AS 64502, internal link

BGP version 4, remote router ID 0.0.0.0

BGP state = Active

Last read 00:03:27, hold time is 180, keepalive interval is 60 seconds

Message statistics:

Inq depth is 0

Outq depth is 0

Sent Rcvd

Opens: 2 0

Notifications: 0 0

Updates: 0 0

Keepalives: 0 0

Route Refresh: 0 0

Capability: 0 0

Total: 2 0

Minimum time between advertisement runs is 5 seconds

For address family: IPv4 Unicast

Community attribute sent to this neighbor(both)

0 accepted prefixes

Connections established 0; dropped 0

Last reset never

Local host: x.y.z.107, Local port: 3433

Foreign host: x.y.z.105, Foreign port: 179

Nexthop: x.y.z.107

Nexthop global: ::

Nexthop local: ::

BGP connection: non shared network

Next connect timer due in 39 seconds

Read thread: off Write thread: off

BGP neighbor is x.y.z.106, remote AS 64502, local AS 64502, internal link

BGP version 4, remote router ID 0.0.0.0

BGP state = Active

Last read 00:03:27, hold time is 180, keepalive interval is 60 seconds

Message statistics:

Inq depth is 0

Outq depth is 0

Sent Rcvd

Opens: 0 0

Notifications: 0 0

Updates: 0 0

Keepalives: 0 0

Route Refresh: 0 0

Capability: 0 0

Total: 0 0

Minimum time between advertisement runs is 5 seconds

For address family: IPv4 Unicast

Community attribute sent to this neighbor(both)

0 accepted prefixes

Connections established 0; dropped 0

Last reset never

Next connect timer due in 46 seconds

Read thread: off Write thread: off

BGP neighbor is x.y.z.108, remote AS 64502, local AS 64502, internal link

BGP version 4, remote router ID 10.10.10.108

BGP state = Established, up for 00:03:22

Last read 00:00:22, hold time is 180, keepalive interval is 60 seconds

Neighbor capabilities:

Route refresh: advertised and received(old & new)

Address family IPv4 Unicast: advertised and received

Message statistics:

Inq depth is 0

Outq depth is 0

Sent Rcvd

Opens: 1 1

Notifications: 0 0

Updates: 5 8

Keepalives: 5 4

Route Refresh: 0 0

Capability: 0 0

Total: 11 13

Minimum time between advertisement runs is 5 seconds

For address family: IPv4 Unicast

Community attribute sent to this neighbor(both)

10 accepted prefixes

Connections established 1; dropped 0

Last reset never

Local host: x.y.z.107, Local port: 2113

Foreign host: x.y.z.108, Foreign port: 179

Nexthop: x.y.z.107

Nexthop global: ::

Nexthop local: ::

BGP connection: non shared network

Read thread: on Write thread: off

BGP neighbor is x.y.z.125, remote AS 64505, local AS 64502, external link

BGP version 4, remote router ID x.y.z.125

BGP state = Established, up for 00:03:22

Last read 00:00:22, hold time is 180, keepalive interval is 60 seconds

Neighbor capabilities:

Route refresh: advertised and received(old & new)

Address family IPv4 Unicast: advertised and received

Message statistics:

Inq depth is 0

Outq depth is 0

Sent Rcvd

Opens: 1 1

Notifications: 0 0

Updates: 6 2

Keepalives: 5 4

Route Refresh: 0 0

Capability: 0 0

Total: 12 7

Minimum time between advertisement runs is 30 seconds

For address family: IPv4 Unicast

Community attribute sent to this neighbor(both)

Inbound path policy configured

Incoming update prefix filter list is *allowed-in

2 accepted prefixes

Connections established 1; dropped 0

Last reset never

Local host: x.y.z.107, Local port: 3430

Foreign host: x.y.z.125, Foreign port: 179

Nexthop: x.y.z.107

Nexthop global: ::

Nexthop local: ::

BGP connection: non shared network

Read thread: on Write thread: off

Checking ip route with both BGPv4 and OSPFv2 running:

vm-test:/home/test# ip route

10.10.117.0/29 via x.y.z.117 dev eth0 proto zebra çBGP note eth0 and via address

10.10.115.0/29 via 10.10.10.115 dev eth1 proto zebra metric 20 çOSPF note eth1 and via address

10.10.109.0/29 via 10.10.10.109 dev eth1 proto zebra metric 20 çOSPF note eth1 and via address

10.10.105.0/29 via 10.10.10.105 dev eth1 proto zebra metric 20 çOSPF note eth1 and via address

10.10.123.0/29 dev eth1 proto kernel scope link src 10.10.123.2

10.10.10.96/27 dev eth1 proto kernel scope link src 10.10.10.123

x.y.z.96/27 dev eth0 proto kernel scope link src x.y.z.123

default via x.y.z.97 dev eth0

Checking netstat –an (note LISTEN and ESTABLISHED for port 179, also LISTEN for 2605 (Quagga bgpd); 2601 is zebra).

vm-xyzst0:/# netstat -an

Active Internet connections (servers and established)

Proto Recv-Q Send-Q Local Address Foreign Address State

tcp 0 0 0.0.0.0:2601 0.0.0.0:* LISTEN

tcp 0 0 0.0.0.0:2605 0.0.0.0:* LISTEN

tcp 0 0 0.0.0.0:179 0.0.0.0:* LISTEN

tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN

tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN

tcp 0 284 x.y.z.125:22 71.182.227.207:2763 ESTABLISHED

tcp 0 0 x.y.z.125:179 x.y.z.107:4336 ESTABLISHED

Checking netstat -rn

vm-xyzst0:~# netstat -rn

Kernel IP routing table

Destination Gateway Genmask Flags MSS Window irtt Iface

10.10.101.0 10.10.10.101 255.255.255.248 UG 0 0 0 eth1

10.10.10.96 x.y.z.103 255.255.255.248 UG 0 0 0 eth0

10.10.117.0 10.10.10.117 255.255.255.248 UG 0 0 0 eth1

10.10.116.0 x.y.z.116 255.255.255.248 UG 0 0 0 eth0

10.10.103.0 x.y.z.103 255.255.255.248 UG 0 0 0 eth0

10.10.119.0 10.10.10.119 255.255.255.248 UG 0 0 0 eth1

10.10.118.0 x.y.z.118 255.255.255.248 UG 0 0 0 eth0

10.10.102.0 x.y.z.102 255.255.255.248 UG 0 0 0 eth0

10.10.113.0 x.y.z.113 255.255.255.248 UG 0 0 0 eth0

10.10.112.0 x.y.z.109 255.255.255.248 UG 0 0 0 eth0

10.10.115.0 x.y.z.115 255.255.255.248 UG 0 0 0 eth0

10.10.114.0 10.10.10.114 255.255.255.248 UG 0 0 0 eth1

10.10.109.0 x.y.z.109 255.255.255.248 UG 0 0 0 eth0

10.10.125.0 0.0.0.0 255.255.255.248 U 0 0 0 eth1

10.10.108.0 x.y.z.108 255.255.255.248 UG 0 0 0 eth0

10.10.111.0 x.y.z.109 255.255.255.248 UG 0 0 0 eth0

10.10.110.0 x.y.z.109 255.255.255.248 UG 0 0 0 eth0

10.10.105.0 10.10.10.105 255.255.255.248 UG 0 0 0 eth1

10.10.104.0 x.y.z.104 255.255.255.248 UG 0 0 0 eth0

10.10.107.0 x.y.z.107 255.255.255.248 UG 0 0 0 eth0

10.10.10.96 0.0.0.0 255.255.255.224 U 0 0 0 eth1

x.y.z.96 0.0.0.0 255.255.255.224 U 0 0 0 eth0

0.0.0.0 x.y.z.97 0.0.0.0 UG 0 0 0 eth0

Checking ip route – For BGP Routing Analytics, see: i6230vlabnet7-BGP_RAN.htm

vm-xyzst0:~# ip route

10.10.101.0/29 via 10.10.10.101 dev eth1 proto zebra metric 20

10.10.10.96/29 via x.y.z.103 dev eth0 proto zebra

10.10.117.0/29 via 10.10.10.117 dev eth1 proto zebra metric 20

10.10.116.0/29 via x.y.z.116 dev eth0 proto zebra

10.10.103.0/29 via x.y.z.103 dev eth0 proto zebra

10.10.119.0/29 via 10.10.10.119 dev eth1 proto zebra metric 20

10.10.118.0/29 via x.y.z.118 dev eth0 proto zebra

10.10.102.0/29 via x.y.z.102 dev eth0 proto zebra

10.10.113.0/29 via x.y.z.113 dev eth0 proto zebra

10.10.112.0/29 via x.y.z.109 dev eth0 proto zebra

10.10.115.0/29 via x.y.z.115 dev eth0 proto zebra

10.10.114.0/29 via 10.10.10.114 dev eth1 proto zebra metric 20

10.10.109.0/29 via x.y.z.109 dev eth0 proto zebra

10.10.125.0/29 dev eth1 proto kernel scope link src 10.10.125.1

10.10.108.0/29 via x.y.z.108 dev eth0 proto zebra

10.10.111.0/29 via x.y.z.109 dev eth0 proto zebra

10.10.110.0/29 via x.y.z.109 dev eth0 proto zebra

10.10.105.0/29 via 10.10.10.105 dev eth1 proto zebra metric 20

10.10.104.0/29 via x.y.z.104 dev eth0 proto zebra

10.10.107.0/29 via x.y.z.107 dev eth0 proto zebra

10.10.10.96/27 dev eth1 proto kernel scope link src 10.10.10.125

x.y.z.96/27 dev eth0 proto kernel scope link src x.y.z.125

default via x.y.z.97 dev eth0

ip route | sort

vm-test:/home/test# ip route | sort

10.10.10.96/27 dev eth1 proto kernel scope link src 10.10.10.123

10.10.101.0/29 via x.y.z.101 dev eth0 proto zebra

10.10.102.0/29 via x.y.z.102 dev eth0 proto zebra

10.10.103.0/29 via x.y.z.103 dev eth0 proto zebra

10.10.104.0/29 via x.y.z.104 dev eth0 proto zebra

10.10.105.0/29 via x.y.z.105 dev eth0 proto zebra

10.10.106.0/29 via x.y.z.106 dev eth0 proto zebra

10.10.107.0/29 via x.y.z.107 dev eth0 proto zebra

10.10.109.0/29 via x.y.z.109 dev eth0 proto zebra

10.10.110.0/29 via x.y.z.110 dev eth0 proto zebra

10.10.111.0/29 via x.y.z.111 dev eth0 proto zebra

10.10.113.0/29 via x.y.z.113 dev eth0 proto zebra

10.10.114.0/29 via x.y.z.114 dev eth0 proto zebra

10.10.115.0/29 via x.y.z.115 dev eth0 proto zebra

10.10.116.0/29 via x.y.z.116 dev eth0 proto zebra

10.10.117.0/29 via x.y.z.117 dev eth0 proto zebra metric 1

10.10.123.0/29 dev eth1 proto kernel scope link src 10.10.123.2

x.y.z.96/27 dev eth0 proto kernel scope link src x.y.z.123

default via x.y.z.97 dev eth0

BGP Update Message example.

Frame 13 (112 bytes on wire, 112 bytes captured)

Arrival Time: Nov 30, 2007 16:46:55.325487000

[Time delta from previous packet: 0.964156000 seconds]

[Time since reference or first frame: 1.039985000 seconds]

Frame Number: 13

Packet Length: 112 bytes

Capture Length: 112 bytes

[Frame is marked: False]

[Protocols in frame: eth:ip:tcp:bgp]

Ethernet II, Src: Xensourc_3f:9c:a1 (00:16:3e:3f:9c:a1), Dst: Xensourc_22:e3:58 (00:16:3e:22:e3:58)

Destination: Xensourc_22:e3:58 (00:16:3e:22:e3:58)

Address: Xensourc_22:e3:58 (00:16:3e:22:e3:58)

.... ...0 .... .... .... .... = IG bit: Individual address (unicast)

.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)

Source: Xensourc_3f:9c:a1 (00:16:3e:3f:9c:a1)

Address: Xensourc_3f:9c:a1 (00:16:3e:3f:9c:a1)

.... ...0 .... .... .... .... = IG bit: Individual address (unicast)

.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)

Type: IP (0x0800)

Internet Protocol, Src: x.y.z.107 (x.y.z.107), Dst: x.y.z.125 (x.y.z.125)

Version: 4

Header length: 20 bytes

Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)

0000 00.. = Differentiated Services Codepoint: Default (0x00)

.... ..0. = ECN-Capable Transport (ECT): 0

.... ...0 = ECN-CE: 0

Total Length: 98

Identification: 0xb25f (45663)

Flags: 0x04 (Don't Fragment)

0... = Reserved bit: Not set

.1.. = Don't fragment: Set

..0. = More fragments: Not set

Fragment offset: 0

Time to live: 1

Protocol: TCP (0x06)

Header checksum: 0xcb29 [correct]

[Good: True]

[Bad : False]

Source: x.y.z.107 (x.y.z.107)

Destination: x.y.z.125 (x.y.z.125)

Transmission Control Protocol, Src Port: 2873 (2873), Dst Port: bgp (179), Seq: 84, Ack: 84, Len: 46

Source port: 2873 (2873)

Destination port: bgp (179)

Sequence number: 84 (relative sequence number)

[Next sequence number: 130 (relative sequence number)]

Acknowledgement number: 84 (relative ack number)

Header length: 32 bytes

Flags: 0x18 (PSH, ACK)

0... .... = Congestion Window Reduced (CWR): Not set

.0.. .... = ECN-Echo: Not set

..0. .... = Urgent: Not set

...1 .... = Acknowledgment: Set

.... 1... = Push: Set

.... .0.. = Reset: Not set

.... ..0. = Syn: Not set

.... ...0 = Fin: Not set

Window size: 5840 (scaled)

Checksum: 0xfc61 [incorrect, should be 0x0fed (maybe caused by checksum offloading?)]

Options: (12 bytes)

NOP

Timestamps: TSval 12429545, TSecr 34891405

Border Gateway Protocol

UPDATE Message

Marker: 16 bytes

Length: 46 bytes

Type: UPDATE Message (2)

Unfeasible routes length: 0 bytes

Total path attribute length: 18 bytes

Path attributes

ORIGIN: IGP (4 bytes)

Flags: 0x40 (Well-known, Transitive, Complete)

0... .... = Well-known

.1.. .... = Transitive

..0. .... = Complete

...0 .... = Regular length

Type code: ORIGIN (1)

Length: 1 byte

Origin: IGP (0)

AS_PATH: 64502 (7 bytes)

Flags: 0x40 (Well-known, Transitive, Complete)

0... .... = Well-known

.1.. .... = Transitive

..0. .... = Complete

...0 .... = Regular length

Type code: AS_PATH (2)

Length: 4 bytes

AS path: 64502

AS path segment: 64502

Path segment type: AS_SEQUENCE (2)

Path segment length: 1 AS

Path segment value: 64502

NEXT_HOP: x.y.z.105 (7 bytes)

Flags: 0x40 (Well-known, Transitive, Complete)

0... .... = Well-known

.1.. .... = Transitive

..0. .... = Complete

...0 .... = Regular length

Type code: NEXT_HOP (3)

Length: 4 bytes

Next hop: x.y.z.105 (x.y.z.105)

Network layer reachability information: 5 bytes

10.10.105.0/29

NLRI prefix length: 29

NLRI prefix: 10.10.105.0 (10.10.105.0)

Note Port Number 179, ACK message example.

Frame 16 (66 bytes on wire, 66 bytes captured)

Arrival Time: Nov 30, 2007 16:46:55.363603000

[Time delta from previous packet: 0.036999000 seconds]

[Time since reference or first frame: 1.078101000 seconds]

Frame Number: 16

Packet Length: 66 bytes

Capture Length: 66 bytes

[Frame is marked: False]

[Protocols in frame: eth:ip:tcp]

Ethernet II, Src: Xensourc_22:e3:58 (00:16:3e:22:e3:58), Dst: Xensourc_3f:9c:a1 (00:16:3e:3f:9c:a1)

Destination: Xensourc_3f:9c:a1 (00:16:3e:3f:9c:a1)

Address: Xensourc_3f:9c:a1 (00:16:3e:3f:9c:a1)

.... ...0 .... .... .... .... = IG bit: Individual address (unicast)

.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)

Source: Xensourc_22:e3:58 (00:16:3e:22:e3:58)

Address: Xensourc_22:e3:58 (00:16:3e:22:e3:58)

.... ...0 .... .... .... .... = IG bit: Individual address (unicast)

.... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)

Type: IP (0x0800)

Internet Protocol, Src: x.y.z.125 (x.y.z.125), Dst: x.y.z.107 (x.y.z.107)

Version: 4

Header length: 20 bytes

Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)

0000 00.. = Differentiated Services Codepoint: Default (0x00)

.... ..0. = ECN-Capable Transport (ECT): 0

.... ...0 = ECN-CE: 0

Total Length: 52

Identification: 0xebd0 (60368)

Flags: 0x04 (Don't Fragment)

0... = Reserved bit: Not set

.1.. = Don't fragment: Set

..0. = More fragments: Not set

Fragment offset: 0

Time to live: 1

Protocol: TCP (0x06)

Header checksum: 0x91e6 [correct]

[Good: True]

[Bad : False]

Source: x.y.z.125 (x.y.z.125)

Destination: x.y.z.107 (x.y.z.107)

Transmission Control Protocol, Src Port: bgp (179), Dst Port: 2873 (2873), Seq: 137, Ack: 183, Len: 0

Source port: bgp (179)

Destination port: 2873 (2873)

Sequence number: 137 (relative sequence number)

Acknowledgement number: 183 (relative ack number)

Header length: 32 bytes

Flags: 0x10 (ACK)

0... .... = Congestion Window Reduced (CWR): Not set

.0.. .... = ECN-Echo: Not set

..0. .... = Urgent: Not set

...1 .... = Acknowledgment: Set

.... 0... = Push: Not set

.... .0.. = Reset: Not set

.... ..0. = Syn: Not set

.... ...0 = Fin: Not set

Window size: 5792 (scaled)

Checksum: 0xd7d6 [correct]

Options: (12 bytes)

NOP

Timestamps: TSval 34891665, TSecr 12429545

[SEQ/ACK analysis]

[This is an ACK to the segment in frame: 15]

[The RTT to ACK the segment was: 0.036999000 seconds]

References/Resources:

See: http://www.infroref.org/i6230vlabnet6-BGP.htm

· Schmied G, Integrated Cisco and UNIX® Network Architectures (Ciscopress, 2005), Lab 10-1, “MPLS,” pp. 445-446.

· Multiprotocol Label Switching: http://datatracker.ietf.org/wg/mpls/charter/, http://en.wikipedia.org/wiki/Multiprotocol_Label_Switching; and BGP: Rekhter and Rosen, "Carrying Label Information in BGP4", RFC 3107, May 2001; and Rosen, Viswanathan, and Callon, "Multiprotocol Label Switching Architecture", RFC 3031, January 2001.

m, n = student domain number {nÎN | ((n ≥ 101) Ù (n ≤ 126))}

x.y.z. = first three octets of assigned routable network addresses for INFS6230.

Valerie J. H. Powell, RMU C&IS; Randall S. Johnson, RMU IT Technical Services

Update: 2011-11-24