We have the same IP Addresses in different PEs. These addreses are not redistributed by routing. These IPs belongs to loopbacks that we use for communication with CEs.
The problem is that the P routers receive these addresses by LDP.
Then in the P routers we have event of this type:
Nov 23 14:02:58.183: %TAGCON-3-DUP_ADDR_RCVD: Duplicate Address 10.10.10.1 advertised by peer 10.1.1.8:0 is already bound to 10.2.1.28:0
Nov 23 14:02:58.183: %TAGCON-3-TDPID: peer 10.1.1.8:0, TDP Id/Addr mapping problem (rcvd TDP address PIE, bind failed).
When the LDP flaps, then the events appears again.
This is not a problem for the traffic, because there are not traffic directed to these addresses, but the logs are fulled of these events.
Are there any method to avoid these events or that LDP announce these addresses?
Unfortunately this can not be filtered as of today. The addresses can be viewed by "show mpls ldp neighbor x.x.x.x". The underlying reason is that a LSR has to find the proper label for a routing table entry. The RIB contains next hop IPs, which typically are assigned to a physical interface. Labels are announced by LDP and neighbors identified by the LDP ID x.x.x.x:0
LDP ID 10.1.1.1:0
route 192.168.1.0/24 via 10.1.2.3
To know which LDP ID, hence which label, should be used for 192.168.1.0/24 the LSRs announce all their IP addresses through LDP.
From section 2.7 in RFC 5036:
"... To enable LSRs to map between a peer LDP Identifier and the peer's addresses, LSRs advertise their addresses using LDP Address and Withdraw Address messages."
So unfortunately for you, the behaviour is part of the LDP standard.
Hope this helps! Please rate all posts.
Without much insight into the assignment of duplicate loopback addresses for PE-CE peering
You can filter out these prefixes to be not advertised by LDP as below.
mpls ldp advertise-labels old-style
mpls ldp advertise-labels for 10
access-list 10 permit 10.1.1.0 0.0.0.255
access-list 10 permit 10.2.1.0 0.0.0.255
access-list 10 deny any