I've been working on an MPLS/VRF lab and I'm a bit confused by MP-BGP address families. When I configured the PE to P routing (within the MPLS core), the BGP neighbors are configured under the VPNv4 address family, like this:   address-family vpnv4   neighbor 10.250.4.1 activate   neighbor 10.250.4.1 send-community extended Now I understand that the VPNv4 address-family is necessary because it tells MP-BGP to include RD/RT info with the advertised prefixes. But when I configure my VRFs in MP-BGP, you can only create them in an IPv4 address family (or IPv6, I suppose). Since the VPNv4 AF's purpose is to include RD/RT info, and a VRF is basically defined by its RD/RT info, shouldn't individual VRFs be configured in the VPNv4 AF? Or is VPNv4 a "special" AF that only exists to share prefixes between P router in the MPLS core? I guess I"m not really clear on the distinction between the IPv4 and VPNv4 address families.       ... View more

I've been playing around with a very basic HSRP Preempt configuration and I can't get my Standby switch to take over as the active. Here's the scenario: Switch 1 is the Active, with Priority set at 105. Switch 2 is the Standby, with Priority left at default (100). Preempt is configured on Switch 2. When both switches are up and operational, the Standby group looks good. For example, when I do a show standby on Switch 1 I get the following: Vlan100 - Group 1   State is Active     2 state changes, last state change 00:25:51   Virtual IP address is 10.10.10.3   Active virtual MAC address is 0000.0c07.ac01     Local virtual MAC address is 0000.0c07.ac01 (v1 default)   Hello time 3 sec, hold time 10 sec     Next hello sent in 0.704 secs   Preemption disabled   Active router is local   Standby router is 10.10.10.2, priority 100 (expires in 10.512 sec)   Priority 105 (configured 105)   Group name is "hsrp-Vl100-1" (default) So if I power down Switch 1, the HSRP and the preemption that I configured on Switch 2 should cause it to take over as the Active switch, correct? But when I power down Switch 2 and then do a show standby on Switch 2, I only get the following: Switch2#show standby Vlan100 - Group 1   State is Init (interface down)     6 state changes, last state change 00:00:26   Virtual IP address is 10.10.10.3   Active virtual MAC address is unknown     Local virtual MAC address is 0000.0c07.ac01 (v1 default)   Hello time 3 sec, hold time 10 sec   Preemption enabled   Active router is unknown   Standby router is unknown   Priority 100 (default 100)   Group name is "hsrp-Vl100-1" (default) Am I doing something wrong? Why does Switch 2 not take over as the Active switch? For your reference, here are the HSRP configs on both Switch 1 and Switch 2: Switch 1: interface Vlan100  ip address 10.10.10.1 255.255.255.0  standby 1 ip 10.10.10.3  standby 1 priority 105 Switch 2: interface Vlan100  ip address 10.10.10.2 255.255.255.0  no ip route-cache  standby 1 ip 10.10.10.3  standby 1 preempt Any insight is appreciated, thanks.       ... View more

I was reading up on BGP route reflection and I read that a Route Reflector (RR) will advertise all received routes to all clients and non-clients. A RR will also advertise (or reflect) routes received from clients as well as routes received from non-clients. So I'm wondering what's the difference between a client and non-client? If a RR receives and reflects routes to/from everyone, what's the point of defining some of the peers as clients and leaving others as regular iBGP peers. The example toplogy in the book I was reading had several iBGP peers configured in a RR cluster and one peer configured as a regular iBGP peer. The regular iBGP peer was peered with the RR. As far as I could tell, the regular iBGP peer was receiving all the same routes as the RR clients and advertising its routes to the RR, which the RR reflected to its clients. So why even bother with the client/non-client distinction? Thanks. ... View more