10-30-2008 01:46 PM
Hi,
Is there another way of filtering the routes you want to import into a vrf because the 'route-target export' and 'route-target import' imports ALL the routes tagged with the given 'asn:xx'. I wanted to have only selected routes imported from one vrf to another. Vrf 'import map' command does not work for me?
Does filtering makes sense or practical at vrf-vrf level? Where do you use 'import map' command?
thanks
resti
10-30-2008 01:56 PM
Resti,
The import and export maps are purposely designed to selectively import/export routes between VRFs.
Regards
10-30-2008 02:09 PM
Thanks Harold for your response.
Do you have an example of this especially the complete route-map used or previous topic citing this example. Cant find a sample fo this in Cisco docs.
thanks,
10-30-2008 02:32 PM
Resti,
Here's a very simple scenario, where you only want 192.168.1.0/24 to be exported from VRF1 to VRF2 and 192.168.2.0/24 to be exported from VRF2 to VRF1.
ip vrf VRF1
rd 1:1
route-target both 1:1
export map toVRF2
!
ip vrf VRF2
rd 1:2
route-target both 1:2
export map toVRF1
!
route-map toVRF1 permit 10
match ip address 2
set extcommunity rt 1:1
!
route-map toVRF2 permit 10
match ip address 1
set extcommunity rt 1:2
!
access-list 1 permit 192.168.1.0
access-list 2 permit 192.168.2.0
!
Regards
10-31-2008 12:21 PM
Hi,
I tried it but it did not work for me. Anything I'm missing? Here's my config, and 'show ip bgp vpn4 all', and IOS c7200-js-mz.124-16a.bin.:
thanks,
!
ip vrf Customer_A
rd 100:110
route-target export 100:1000
route-target import 100:1000
!
ip vrf Customer_B
rd 100:120
export map CE5_Export
route-target export 100:2000
route-target import 100:2000
!
!
access-list 99 permit 10.30.30.0 0.0.0.255
access-list 99 permit 10.40.40.0 0.0.0.255
!
route-map CE5_Export permit 10
match ip address 99
set extcommunity rt 100:1000
!
PE4#sh ip bgp vpnv4 all
BGP table version is 56, local router ID is 10.128.1.6
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: 100:110 (default for vrf Customer_A)
*>i10.128.1.7/32 10.128.1.3 0 100 0 65100 i
*> 10.128.1.10/32 10.128.4.14 0 0 65400 i
*>i10.128.4.0/30 10.128.1.3 0 100 0 65100 i
r> 10.128.4.12/30 10.128.4.14 0 0 65400 i
*>i172.100.1.0/24 10.128.1.3 0 100 0 65100 i
*> 172.100.4.0/24 10.128.4.14 0 0 65400 i
*> 192.168.1.0 10.128.4.14 0 0 65400 i
*> 192.168.2.0 10.128.4.14 0 0 65400 i
*> 192.168.3.0 10.128.4.14 0 0 65400 i
Route Distinguisher: 100:120 (default for vrf Customer_B)
*> 10.30.30.0/24 10.128.5.14 0 0 65500 i
*> 10.40.40.0/24 10.128.5.14 0 0 65500 i
*> 10.128.1.11/32 10.128.5.14 0 0 65500 i
r> 10.128.5.12/30 10.128.5.14 0 0 65500 i
PE4#
10-31-2008 02:17 PM
Can you please post the output of "sh ip bgp v a 10.30.30.0"
Regards
11-03-2008 08:38 AM
Hi,
Here's the output of that command:
PE4#sh ip bgp vpnv4 all 10.30.30.0
BGP routing table entry for 100:120:10.30.30.0/24, version 46
Paths: (1 available, best #1, table Customer_B)
Advertised to update-groups:
1
65500
10.128.5.14 from 10.128.5.14 (10.128.1.11)
Origin IGP, metric 0, localpref 100, valid, external, best
Extended Community: RT:100:2000
mpls labels in/out 32/nolabel
PE4#
brgds,
11-06-2008 04:46 AM
Hello,
I would try to remove "route-target export 100:2000" from the the following configuration:
ip vrf Customer_B
rd 100:120
export map CE5_Export
route-target export 100:2000
route-target import 100:2000
Also, I would add a further statement in the route-map for the remaining prefixes, such as:
route-map CE5_Export permit 20
set extcommunity rt 100:2000
In all the examples I have seen, when they are using an "export map", they are not using it together with "route-target export" . I do not know why this is so. In your case, it seems that "route-target export" overrides the "export map". In the "export map" command documentation the expected behavior in such a situation is not defined. Interestingly, the "import map" command is required together with "route-target import" (for automatic route filtering to work I guess).
Kind Regards,
M.
11-06-2008 09:04 AM
Hi,
Thanks M for yr reply. I did not have time to try your suggestion yet but I think I got one solution and it's consistently working for me.
I noticed that you have to clear vrf's bgp session to make sure changes take into effect otherwise SOME changes esp export/import map under 'ip vrf' section do not take into effect automatically.
Below is the command I used on the PE. With this my original configuration works.
#clear ip bgp vrf
e.g.
PE4# clear ip bgp vrf Customer_B ipv4 unicast 65500 soft
brgds,
11-06-2008 09:15 AM
Resti,
I ran into a similar issue at initial configuration. The workaround was to remove the route-map and re-apply it. A reload also fixed this issue.
Regards
11-06-2008 10:19 AM
Yeah, i guess sometimes we to live with these 'undocumented features'!
Thanks&brgds,
11-06-2008 10:27 AM
Hi,
Please consider the command "set extcommunity rt
Harold,
What might explain the observed behaviour: modification of the export route-map will NOT trigger a re-import into BGP. So a "clear ip route" or a "clear ip bgp vpnv4 vrf..." can be required.
I usually first configure the route-map and afterwards the export map command. Usually this assures proper marking with the desired values.
Regards,
Martin
11-06-2008 11:06 AM
Martin,
Excellent observation. It is always a good idea to configure the route-map before applying it.
Regards
11-07-2008 08:14 AM
Hi Martin,
Thanks for the tips. I tested it and understand the effect of having the keyword 'additive' in it. Definitely useful feature.
Best regards,
05-10-2014 06:51 AM
Hi Harold,
How does VRF export work? Does it export the route regardless or does it have to be present? In your example when you export 192.168.1.0/24 from VRF1 to VRF2, what happens if the 192.168.1.0/24 route goes away from the routing table? Will the export remove that route from VRF2 automatically?
Thanks,
Sam
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