Brocade TurboIron 24X Series Configuration Guide - Manual (Page 723)

Brocade TurboIron 24X Series Configuration Guide 689
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Optional configuration tasks
In this example, the Layer 3 Switch cannot reach 10.240.0.0/24, because the next-hop IP address
for the route is an IBGP route instead of an IGP route, and thus is considered unreachable by the
Layer 3 Switch. Here is the IP route table entry for the BGP route next-hop gateway
(10.102.0.1/24).
The route to the next-hop gateway is a BGP route, not an IGP route, and thus cannot be used to
reach 10.240.0.0/24. In this case, the Layer 3 Switch tries to use the default route, if present, to
reach the subnet that contains the BGP route next-hop gateway.
Example when recursive route lookups are enabled
When recursive next-hop lookups are enabled, the Layer 3 Switch recursively looks up the next-hop
gateways along the route until the Layer 3 Switch finds an IGP route to the BGP route destination.
Here is an example.
TurboIron#show ip bgp route
Total number of BGP Routes: 5
Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST C:CONFED_EBGP D:DAMPED
H:HISTORY I:IBGP L:LOCAL M:MULTIPATH S:SUPPRESSED
Prefix Next Hop Metric LocPrf Weight Status
1 0.0.0.0/0 10.1.0.2 0 100 0 BI
AS_PATH: 65001 4355 701 80
2 10.2.0.0/24 10.0.0.1 1 100 0 BI
AS_PATH: 65001 4355 1
3 10.4.0.0/24 10.1.0.2 0 100 0 BI
AS_PATH: 65001 4355 701 1 189
4 10.240.0.0/24 10.102.0.1 1 100 0 I
AS_PATH: 65001 4355 3356 7170 1455
5 10.250.0.0/24 10.157.24.1 1 100 0 I
AS_PATH: 65001 4355 701
TurboIron#show ip route 10.102.0.1
Total number of IP routes: 37
Network Address NetMask Gateway Port Cost Type
10.102.0.0 255.255.255.0 10.0.0.1 1 1 B
TurboIron#show ip route 10.240.0.0/24
Total number of IP routes: 37
Network Address NetMask Gateway Port Cost Type
0.0.0.0 0.0.0.0 10.0.0.202 1 1 S