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Cisco Set Local-Preference Question

Hello Experts,

Each time I set the local-preference to a value greater than a route recievied via and internal bgp link I lose the the route.

For example the following out shows that there are three routes to network 1.1.1.1 However, when I set the local preference on 170.70.7.2 to a value greater than the default of 100 I lose the route via 172.22.16.3

Can someone please help?

EPUK-LAB1-C7204-2_THN#show ip bgp vpnv4 vrf eti
BGP table version is 26, local router ID is 172.22.16.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, x best-external
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:2 (default for vrf eti)
* i1.1.1.1/32       172.22.16.3              0    100      0 35526 ?
*                   180.80.8.4                             0 35526 ?
*>                  170.70.7.2                             0 35526 ?
* i2.2.2.2/32       172.22.16.3              0    100      0 35526 ?
*                   180.80.8.4               0             0 35526 ?
*>                  170.70.7.2               0             0 35526 ?
*>i3.3.3.3/32       172.22.16.3              0    100      0 ?
*> 4.4.4.4/32       0.0.0.0                  0         32768 ?
* i9.9.9.0/24       172.22.16.3              0    100      0 35526 ?
*                   180.80.8.4                             0 35526 ?
*>                  170.70.7.2                             0 35526 ?
*> 10.100.100.0/24  0.0.0.0                  0         32768 ?
* i                 172.22.16.3              0    100      0 ?
* i41.190.1.0/24    172.22.16.3              0    100      0 35526 ?
*                   180.80.8.4               0             0 35526 ?
*>                  170.70.7.2               0             0 35526 ?
*  160.60.6.0/24    180.80.8.4                             0 35526 ?
*                   170.70.7.2                             0 35526 ?
*>i                 172.22.16.3              0    100      0 ?

Please see attached for configurations
12-23-10--EPUK-LAB1-C7204-1-EGH-.txt
12-23-12--EPUK-LAB1-C7204-2-THN-.txt
ASKER CERTIFIED SOLUTION
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Garry Glendown
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Garry,

Thanks for responding. I'm going to add the local-preference and show you the new output in 3 minutes
Garry the following show ip bgp for 1.1.1.1 are without local_preference added

EPUK-LAB1-C7204-2_THN#show ip bgp vpnv4 vrf eti
BGP table version is 26, local router ID is 172.22.16.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, x best-external
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:2 (default for vrf eti)
* i1.1.1.1/32       172.22.16.3              0    100      0 35526 ?
*                   180.80.8.4                             0 35526 ?
*>                  170.70.7.2                             0 35526 ?
* i2.2.2.2/32       172.22.16.3              0    100      0


EPUK-LAB1-C7204-2_THN#show ip bgp vpnv4 vrf eti 1.1.1.1
BGP routing table entry for 1:2:1.1.1.1/32, version 20
Paths: (5 available, best #4, table eti)
  Advertised to update-groups:
     138        139      
  35526
    172.22.16.3 from 172.22.16.3 (172.22.16.3)
      Origin incomplete, metric 0, localpref 100, valid, internal
      Extended Community: RT:1:2
      mpls labels in/out 41/nolabel
  35526
    180.80.8.4 from 180.80.8.4 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external
      Extended Community: RT:1:2
      mpls labels in/out 41/nolabel
  35526, (received-only)
    180.80.8.4 from 180.80.8.4 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external
      mpls labels in/out 41/nolabel
  35526
    170.70.7.2 from 170.70.7.2 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external, best
      Extended Community: RT:1:2
      mpls labels in/out 41/nolabel
  35526, (received-only)
    170.70.7.2 from 170.70.7.2 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external
      mpls labels in/out 41/nolabel
EPUK-LAB1-C7204-2_THN#

You will notice that there are three paths/routes to 1.1.1.1

a). 172.22.16.3
b). 180.80.8.4
c). 170.70.7.2

Now, the following is after I create a local-preference of 150 on 170.70.7.X

EPUK-LAB1-C7204-2_THN#show ip bgp vpnv4 vrf eti
BGP table version is 33, local router ID is 172.22.16.4
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, m multipath, b backup-path, x best-external
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:2 (default for vrf eti)
*  1.1.1.1/32       180.80.8.4                             0 35526 ?
*>                  170.70.7.2                    120      0 35526 ?
*  2.2.2.2/32       180.80.8.4               0             0 35526 ?
*>                  170.70.7.2               0    120      0 35526 ?
*>i3.3.3.3/32       172.22.16.3              0    100      0 ?
*> 4.4.4.4/32       0.0.0.0                  0         32768 ?
*  9.9.9.0/24       180.80.8.4                             0 35526 ?
*>                  170.70.7.2                    120      0 35526 ?
*> 10.100.100.0/24  0.0.0.0                  0         32768 ?
* i                 172.22.16.3              0    100      0 ?
*  41.190.1.0/24    180.80.8.4               0             0 35526 ?
*>                  170.70.7.2               0    120      0 35526 ?
*  160.60.6.0/24    180.80.8.4                             0 35526 ?
*>                  170.70.7.2                    120      0 35526 ?
* i                 172.22.16.3              0    100      0 ?
*> 170.70.7.0/24    0.0.0.0                  0         32768 ?
*                   180.80.8.4               0             0 35526 ?
*                   170.70.7.2               0    120      0 35526 ?
*> 172.22.16.3/32   10.100.100.1             0         32768 ?
* i                 172.22.16.3              0    100      0 ?
*> 172.22.16.4/32   0.0.0.0                  0         32768 ?
* i                 172.22.16.3              0    100      0 ?
*> 180.80.8.0/24    0.0.0.0                  0         32768 ?
*                   180.80.8.4               0             0 35526 ?
*                   170.70.7.2               0    120      0 35526 ?
*  190.90.9.0/24    180.80.8.4                             0 35526 ?
*>                  170.70.7.2                    120      0 35526 ?
* i                 172.22.16.3              0    100      0 ?
*  192.168.1.0      180.80.8.4               0             0 35526 ?
*>                  170.70.7.2               0    120      0 35526 ?

You notice that 172.22.16.3 has disappeared.

I think I understand why, but I don't know how to overcome it....

Cheers

Carlton
Do a "show ip bgp vpnv4 vrf eti 1.1.1.1" in the second setup - most likely you will still get the route listed, but due to the higher local preference, it is not shown on the list output ...
Hi Garry, route still not listed.

EPUK-LAB1-C7204-2_THN#  show ip bgp vpnv4 vrf eti 1.1.1.1
BGP routing table entry for 1:2:1.1.1.1/32, version 27
Paths: (4 available, best #3, table eti)
  Advertised to update-groups:
     138        139      
  35526
    180.80.8.4 from 180.80.8.4 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external
      Extended Community: RT:1:2
      mpls labels in/out 41/nolabel
  35526, (received-only)
    180.80.8.4 from 180.80.8.4 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external
      mpls labels in/out 41/nolabel
  35526
    170.70.7.2 from 170.70.7.2 (2.2.2.2)
      Origin incomplete, localpref 120, valid, external, best
      Extended Community: RT:1:2
      mpls labels in/out 41/nolabel
  35526, (received-only)
    170.70.7.2 from 170.70.7.2 (2.2.2.2)
      Origin incomplete, localpref 100, valid, external
      mpls labels in/out 41/nolabel
EPUK-LAB1-C7204-2_THN#


Any thoughts?
Garry/Experts,

Below is the output from the iBGP router directly connected:

EPUK-LAB1-C7204-1_EGH1#show ip bgp vpnv4 vrf eti
BGP table version is 86, local router ID is 172.22.16.3
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
Route Distinguisher: 1:2 (default for vrf eti)
*>i1.1.1.1/32       172.22.16.4              0    120      0 35526 ?
*                   190.90.9.4               0             0 35526 ?
*                   160.60.6.2               0             0 35526 ?
*>i2.2.2.2/32       172.22.16.4              0    120      0 35526 ?

This might help in helping me....
Any help with this?
I can't really explain the behavior of the show-output, but what exactly is the problem of the route not being listed anymore? If you increase the local preference for another link, and it's higher than the "lost" route, that then not visible path would not be used anyway, as a higher local preference path is available ... ?!
Cheers