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Basic MPLS CE config questions

OTSpotConsult
Level 1
Level 1

We have been using an MPLS system for a few months to move voip between 3 sites.  Each site had an extra interface to use for data if we wish.  Two of the sites use a dedicated T1 for a WAN which will stay.  I would like to link the third site to the main site using the MPLS.  I have gotten somewhat poor response for info from my telco provider.  They did send me the putty log from their routere which is at our sites(PE I would assume)  basically the two cities involved and the ip's the telco gave the if's are CityA-10.1.2.1/24 CityB-10.1.6.1/24.  That is all I got from them.  I have configured a 1941router at each site with the ip's of:

CityA GE0/1 10.1.2.3/24 and GE0/0 192.168.1.25/24

ip route 10.1.6.0 255.255.255.0 10.1.2.1

ip route 192.168.3.0 255.255.255.0 10.1.6.3

CityB GE0/1 10.1.6.3/24 and GE0/0 192.168.3.27/24

ip route 10.1.2.0 255.255.255.0 10.1.6.1

ip route 192.168.1.0 255.255.255.0 10.1.2.3

I can ping the 10.1.x.x from either CE router and all respond.  I can not get to either 192.168.1.25 or 192.168.3.27.

The above works for simple routing across our other T1s without a problem.  I have also modified the second line of each to be ip route Dest Mask IFname nexthop but adding the gigbitethernet0/1 does not seem to matter.

Looking into what they gave me, I see in the putty log from the provider that they are using BGP at least to some extent.  None of my internal addresses are represented in their bgp statements and that seems like it would be a problem.  From the reading I've been doing they should be mentioned as network or neighbor.

Any ideas would be appreciated.  The telco gives terrible half answers so I have to drag info out of them and I figured if nothing else you folks could suggest what I should ask of them.  Thanks for your help.

1 Reply 1

Giuseppe Larosa
Hall of Fame
Hall of Fame

Hello OTSpotConsult,

>> I can ping the 10.1.x.x from either CE router and all respond.  I can not get to either 192.168.1.25 or 192.168.3.27.

The above works for simple routing across our other T1s without a problem.

Be aware that if you have bought an MPLS L3 VPN service you need to communicate to the SP the IP networks that you want to add to the VPN.

You need to say them : " please add a static route towards CityA CE for network 192.168.1.0/24 and a static route for 192.168.3.0/24 towards City B CE"

This is needed because MPLS L3 VPN uses a peer model:

the neighbor of your CE is a PE router so it needs to be configured you haven't total control of IP routing.

However, there are great scalability advantages in this model as when adding a new site no changes are needed in existing sites as SP signalling plane takes care of advertising new site IP subnets everywhere is needed

Hope to help

Giuseppe

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