From: my-ccie-test@libero.it
Date: Wed Feb 16 2005 - 11:59:27 GMT-3
Hy guys,
I have a question about MPLS-VPN forwarding.
Here is the scenario:
CE1---PE(R1)----P----PE(R2)---CE2
for example, in this case I configure a static route on R1 with next hop received dynamically via MP-BGP from R2:
R1#ip route vrf VPN_XXX 192.168.10.0 255.255.255.0 10.188.127.5
R1#p vrf VPN_XXX 10.188.127.5
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.188.127.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/21/24 ms
R1#p vrf VPN_XXX 192.168.10.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.10.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/21/24 ms
R1#sh ip rou vrf VPN_XXX 192.168.10.1
Routing entry for 192.168.10.0/24
Known via "static", distance 1, metric 0
Routing Descriptor Blocks:
* 10.188.127.5
Route metric is 0, traffic share count is 1
R1#sh ip rou vrf VPN_XXX 10.188.127.5
Routing entry for 10.188.127.5/32
Known via "bgp yyy", distance 200, metric 0
Tag xxx, type internal
Last update from 172.16.13.1 1w6d ago
Routing Descriptor Blocks:
* 172.16.13.1 (Default-IP-Routing-Table), from 172.16.12.2, 1w6d ago
Route metric is 0, traffic share count is 1
AS Hops 2
#sh ip bgp vpn vrf VPN_XXX tags | i 10.188.127.5
10.188.127.5/32 172.16.13.1 notag/6871
#sh ip cef vrf VPN_XXX 192.168.10.0 255.255.255.0 det
151.99.125.0/24, version 127910, per-destination sharing
0 packets, 0 bytes
Flow: AS 0, mask 24
tag information from 10.188.127.5/32, shared
local tag: VPN-route-head
fast tag rewrite with
Recursive rewrite via 172.16.13.1/32, tags imposed {6871}
via 10.188.127.5, 0 dependencies, recursive
next hop 172.16.12.2, FastEthernet5/1/0 via 10.188.127.5/32
valid adjacency
tag rewrite with
Recursive rewrite via 172.16.13.1/32, tags imposed {6871}
Recursive load sharing using 172.16.13.1/32.
R2#sh ip rou vrf VPN_XXX 192.168.10.1
Subnet not in table%
it assigns the same label at both routes (one for static route and one for next hop dinamically received via MP-BGP from R2).
it seems PE is able to transport packets destined to 192.168.10.0/24 without any MP-BGP advertisement about this network.
In fact I can ping from R1 both next hop and an host of subnet 192.168.1.0/24
the questions is:
is this behaviour tipical of MPLS network?
thanks
Max
This archive was generated by hypermail 2.1.4 : Thu Mar 03 2005 - 08:51:21 GMT-3