Re: [mpls-linux-general] MPLS and virtual interfaces
Status: Beta
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From: Alessandro De R. <ale...@ho...> - 2006-01-04 12:42:17
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James, thanks for your reply. This is the simple scenario I am trying to simulate with NCTUns: Host1 -----------------LER1 ------------------- LER2 ---------------- Host2 1.0.1.1 1.0.1.2 1.0.3.1 1.0.3.2 1.0.2.2 1.0.2.1 Where LER1 should create the MPLS stack and LER2 should remove it. Host1 and Host2 respectively send and receive ipv4 packets. I am trying to configure LER1 (from its rlogin shell) entering the following instructions: mpls nhlfe add key 0 ---> key: 0x00000002 mpls nhlfe change key 0x2 instructions push gen 1000 nexthop eth2 ipv4 1.0.3.2 ---> mpls nhlfe change key 0x2 instructions push gen 1000 nexthop tun4 ipv4 1.0.3.2 ---> RTNETLINK answers: Operation not permitted Eth2 is the outgoing interface of LER1 (ip address 1.0.3.1) which corresponds to the virtual interface tun4. Exchanging eth2 with tun4 does not eliminate the RTNETLINK error. The strange fact is that if I enter any other address which doesn't belong to my simulated network (i mean an invented address) I do not get the error. For example: mpls nhlfe change key 0x2 instructions push gen 1000 nexthop eth2 ipv4 153.153.153.153 (this network doesn't exist) ---> mpls nhlfe change key 0x2 instructions push gen 1000 nexthop tun4 ipv4 153.153153.153 mpls nhlfe show ---> NHLFE entry key 0x00000002 mtu 1496 propagate_ttl ---> push gen 1000 set tun4 ipv4 153.153.153.153 (0 bytes, 0 pkts, 0 dropped) But obviously MPLS forwarding is then not enabled, since the network configuration is wrong. The only thing I can think about is the way this simulator addresses packets: probably the point is not this, but every ip address in NCTUns is 1.0.x.x and when a sending node 1.0.A.B has to send packets to a destination node 1.0.C.D, it uses A.B.C.D as destination address. And although this mechanism should be hidden to the user i can still see strange A.B.C.D addresses in my routing tables. I don't know if these informations can be useful to you, but I am still not able to forward any MPLS packet in my simulated network. Can you help me in any way? Alessandro De Rosa |