Appendices : BGP Advanced Routing

Verifying BGP Configuration
Topics:
Viewing BGP Routes
The figure below shows a basic BGP topology where a SonicWALL security appliance is configured for BGP to connect to two routers on two different ASs.
Figure 53. BGP topology
The routes in the FIB for this network can be viewed either in the SonicOS GUI or by using the CLI.
Topics:
Viewing FIB routes in the GUI
A summary of the BGP configuration can be viewed on the SonicOS GUI through the Network > Routing page by clicking the BGP Status button, located at the top of the page next to the Routing Mode drop-down menu. The BGP Status window displays the output of the show ip bgp summary and show ip bgp neighbor commands.
The BGP routes in the FIB can also be viewed on the SonicOS GUI in the Routing Policies table on the Network > Routing page.
Viewing FIB Routes in the CLI
To view the FIB routes in the CLI, perform the following commands:
SonicWALL> configure
(config[SonicWALL])> route ars-nsm
 
ZebOS version 7.7.0 IPIRouter 7/2009
ARS NSM>show ip route
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
* - candidate default
 
B 7.6.7.0/24 [20/0] via 10.50.165.228, X1, 05:08:31
B 199.199.0/16 [20/0] via 10.50.165.237, X1, 05:08:31
C 10.50.165.192/26 is directly connected, X1
C 127.0.0.0/8 is directly connected, lo0
C 12.34.5.0/24 is directly connected, X0
Viewing RIB Routes in the CLI
To view the RIB routes in the CLI, enter the show ip bgp command:
ARS BGP>show ip bgp
BGP table version is 98, local router ID is 10.50.165.233
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, l - labeled
S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 7.6.7.0/24 10.50.165.228 0 0 7675 i
*> 12.34.5.0/24 0.0.0.0 100 32768 i
*> 199.199.0.0/16 10.50.165.228 0 0 7675 9999 i
Total number of prefixes 3
Configuring BGP Logging
SonicWALL BGP offers a comprehensive selection of debug commands to display log events related to BGP traffic. BGP logging can be configured on the CLI by using the debug bgp command followed by of the following keywords:
 
To disable BGP debugging, enter the “no” form of the command. For example, to disable event debugging, type the no debug events command.
BGP log messages can also be viewed on the SonicOS GUI on the Log > View page. BGP messages are displayed as part of the Advanced Routing category of log messages.
The above message indicates that an update to the outgoing RIB was denied because the router from which the update was received was not directly connected to the appliance.
To allow for BGP peers that are not directly connected, use the ebgp-multihop keyword with the neighbor command. For example:
neighbor 10.50.165.228 ebgp-multihop