BGP Routes After Policy Application

The following example shows the routes in the BGP routing table at Router A after applying the custFilter inbound policy:

* Switch.55 # show bgp route all
Routes:
Destination       Peer           Next-Hop        LPref Weight MED    AS-Path
-----------------------------------------------------------------------------------
*>i  10.1.1.0/24       10.10.10.2     10.10.10.2      100   1      100    64505 64496 0
*>i  10.1.2.0/24       10.10.10.2     10.10.10.2      100   1      100    64505 64496 0
*>i  10.1.3.0/24       10.10.10.2     10.10.10.2      100   1      100    64505 64496 0
*>i  10.1.34.0/24      10.10.10.2     10.10.10.2      100   1      100    64505 64499
Flags: (*) Preferred BGP route, (>) Active, (d) Suppressed, (h) History
(s) Stale, (m) Multipath, (u) Unfeasible
Origin: (?) Incomplete, (e) EGP, (i) IGP
BGP Route Statistics
Total Rxed Routes : 5
Feasible Routes   : 4
Active Routes     : 4
Rejected Routes   : 1
Unfeasible Routes : 0
Route Statistics on Session Type
Routes from Int Peer: 0
Routes from Ext Peer: 4

Route 172.16.1.0/24 is not present in the BGP routing table shown above.

The next example shows that the MED and community values are set as defined in the policy.

* Switch.56 # show bgp route detail all
Routes:
Route: 10.1.1.0/24, Peer 10.10.10.2, BEST, Active
Origin IGP, Next-Hop 10.10.10.2, LPref 100, MED 100
Weight 1,
As-PATH: 64505 64496 0
Community: 2342:6788
Route: 10.1.2.0/24, Peer 10.10.10.2, BEST, Active
Origin IGP, Next-Hop 10.10.10.2, LPref 100, MED 100
Weight 1,
As-PATH: 64505 64496 0
Community: 2342:6788
Route: 10.1.3.0/24, Peer 10.10.10.2, BEST, Active
Origin IGP, Next-Hop 10.10.10.2, LPref 100, MED 100
Weight 1,
As-PATH: 64505 64496 0
Community: 2342:6788
Route: 10.1.34.0/24, Peer 10.10.10.2, BEST, Active
Origin IGP, Next-Hop 10.10.10.2, LPref 100, MED 100
Weight 1,
As-PATH: 64505 64499
Community: 2342:6788
BGP Route Statistics
Total Rxed Routes : 5
Feasible Routes   : 4
Active Routes     : 4
Rejected Routes   : 1
Unfeasible Routes : 0
Route Statistics on Session Type
Routes from Int Peer: 0
Routes from Ext Peer: 4

View the routes that are denied at Router A.

* Switch.57 # show bgp neighbor 10.10.10.2 rejected-routes all
Rejected Routes:
Destination       Peer           Next-Hop        LPref Weight MED    AS-Path
---------------------------------------------------------------------------------
i  172.16.1.0/24     10.10.10.2     10.10.10.2      0     1      0      64505
Flags: (*) Preferred BGP route, (>) Active, (d) Suppressed, (h) History
(s) Stale, (m) Multipath, (u) Unfeasible
Origin: (?) Incomplete, (e) EGP, (i) IGP
BGP Route Statistics
Total Rxed Routes : 5
Rejected Routes   : 1
Unfeasible Routes : 0

The next command example shows the denied route as an inactive route.

The routes were updated because soft-reset is configured for this neighbor.

* Switch.61 # show bgp neighbor 10.10.10.2 received-routes all
Routes:
Destination       Peer           Next-Hop        LPref Weight MED    AS-Path
Destination       Peer           Next-Hop        LPref Weight MED    AS-Path
---------------------------------------------------------------------------------
i  172.16.1.0/24     10.10.10.2     10.10.10.2      0     1      0      64505
*>i  10.1.1.0/24       10.10.10.2     10.10.10.2      100   1      100    64505 64496 0
*>i  10.1.2.0/24       10.10.10.2     10.10.10.2      100   1      100    64505 64496 0
*>i  10.1.3.0/24       10.10.10.2     10.10.10.2      100   1      100    64505 64496 0
*>i  10.1.34.0/24      10.10.10.2     10.10.10.2      100   1      100    64505 64499
Flags: (*) Preferred BGP route, (>) Active, (d) Suppressed, (h) History
(s) Stale, (m) Multipath, (u) Unfeasible
Origin: (?) Incomplete, (e) EGP, (i) IGP
BGP Route Statistics
Total Rxed Routes : 5
Feasible Routes   : 4
Active Routes     : 4
Rejected Routes   : 1
Unfeasible Routes : 0

The following command examples show that the denied routes are not transmitted to the neighbors:

* Switch.58 # show bgp neighbor 10.20.20.2 transmitted-routes all
Advertised Routes:
Destination                  Next-Hop        LPref Weight MED    AS-Path
-----------------------------------------------------------------------------
>i  10.1.1.0/24                  10.20.20.1      0            100    64500 64505 64496 0
>i  10.1.2.0/24                  10.20.20.1      0            100    64500 64505 64496 0
>i  10.1.3.0/24                  10.20.20.1      0            100    64500 64505 64496 0
>i  10.1.34.0/24                 10.20.20.1      0            100    64500 64505 64499
Flags: (*) Preferred BGP route, (>) Active, (d) Suppressed, (h) History
(s) Stale, (m) Multipath, (u) Unfeasible
Origin: (?) Incomplete, (e) EGP, (i) IGP
BGP Route Statistics
Advertised Routes : 4
* Switch.59 # show bgp neighbor 10.20.20.2 transmitted-routes detail all
Advertised Routes:
Route: 10.1.1.0/24, Active
Origin IGP, Next-Hop 10.20.20.1, MED 100
As-PATH: 64500 64505 64496 0
Route: 10.1.2.0/24, Active
Origin IGP, Next-Hop 10.20.20.1, MED 100
As-PATH: 64500 64505 64496 0
Route: 10.1.3.0/24, Active
Origin IGP, Next-Hop 10.20.20.1, MED 100
As-PATH: 64500 64505 64496 0
Route: 10.1.34.0/24, Active
Origin IGP, Next-Hop 10.20.20.1, MED 100
As-PATH: 64500 64505 64499
BGP Route Statistics
Advertised Routes : 4