[Xorp-users] help please my multicasting is not working

Pavlin Radoslavov pavlin at icir.org
Thu Jan 17 12:54:27 PST 2008


GDS.Marshall <gdsm at tgfslp.dalmany.co.uk> wrote:

> I have read the xorp documentation (including that on multicasting), I
> have looked at the example configuration for multicasting, I have googled
> till the cows come home, I have read the mailing list, even back as far as
> 2005, but for the life of me I can not get this working.

The reason it didn't work for you is very simple.
Mtrace requires special support from the multicast routers, and
currently the XORP implementation doesn't contain it.

It is on our TODO list, but right now there is IETF activity to
generate a spec for the mtrace protocol, so our preference is to
have an implementation that is based on the new spec.
If I remember correctly, the existing mtrace tool is based on
Internet Drafts that have expired long time ago.

The reason that it appears to work in one direction is probably
accidental.

Regards,
Pavlin

> Would anyone have any suggestions on what to check or change etc. please?
> 
> ISP ---- cisco 1700 ---- linux xorp ---- LAN
>         DSL        ^     ^         ^        ^
>        82.70.154.150     |    192.168.4.3   192.168.4.0/24
>                  82.70.154.145
> 
> on the cisco 1700 if I do an mtrace, it succeeds.
> mtrace 81.20.48.1 82.70.154.145 233.153.34.2
> Type escape sequence to abort.
> Mtrace from 81.20.48.1 to 82.70.154.145 via group 233.153.34.2
> From source (master1.gcapmedia.net) to destination (ns0.dalmany.co.uk)
> Querying full reverse path...
>  0  spitfire.tgfslp.dalmany.co.uk (82.70.154.145)
> -1  gatekeeper.dalmany.co.uk (82.70.154.150) PIM  [default]
> -2  master1.gcapmedia.net (81.20.48.1)
> 
> If I run mtrace from a laptop on the 192.168.4.0/24 network
> /usr/local/bin/mtrace 81.20.48.1 192.168.4.50 233.153.34.2
> Mtrace from 81.20.48.1 to 192.168.4.50 via group 233.153.34.2
> Querying full reverse path... * switching to hop-by-hop:
>   0  hp-laptop.local (192.168.4.50)
>  -1  * * *
>  -2  * * *
>  -3  * * *
>  -4  * * * ...giving up
> Timed out receiving responses
> Perhaps no local router has a route for source 81.20.48.1
> 
> but if I look in xorp, it does
> xorpsh> show route table ipv4 multicast final
> 0.0.0.0/0       [fib2mrib(254)/65535]
>                 > to 82.70.154.150 via eth1/eth1
> 192.168.4.0/24  [connected(0)/0]
>                 > via eth0/eth0
> 82.70.154.144/29        [connected(0)/0]
>                 > via eth1/eth1
> 
> next I tried mtrace from the outside interface of the linux xorp
> /usr/local/bin/mtrace 81.20.48.1 82.70.154.145 233.153.34.2
> Mtrace from 81.20.48.1 to 82.70.154.145 via group 233.153.34.2
> Querying full reverse path... * switching to hop-by-hop:
>   0  spitfire.tgfslp.dalmany.co.uk (82.70.154.145)
>  -1  * * *
>  -2  * * *
>  -3  * * *
>  -4  * * * ...giving up
> Timed out receiving responses
> Perhaps no local router has a route for source 81.20.48.1
> 
> Here are a few show commands and results
> xoprsh> show pim neighbors
> Interface    DRpriority NeighborAddr    V Mode   Holdtime Timeout
> eth1                  1 82.70.154.150   2 Sparse      105      98
> 
> xorpsh> show pim interface
> Interface    State    Mode   V PIMstate Priority DRaddr          Neighbors
> eth0         UP       Sparse 2 DR              1 192.168.4.3             0
> eth1         UP       Sparse 2 NotDR           1 82.70.154.150           1
> register_vif UP       Sparse 2 DR              1 192.168.4.3             0
> 
> why is eth1 "NotDR?"
> 
> xorpsh> show pim mrib
> DestPrefix         NextHopRouter   VifName VifIndex MetricPref Metric
> 0.0.0.0/0          82.70.154.150   eth1    1               254  65535
> 82.70.154.144/29   82.70.154.145   eth1    1                 0      0
> 192.168.4.0/24     192.168.4.3     eth0    0                 0      0
> 
> xorpsh> ping 224.0.0.1
> PING 224.0.0.1 (224.0.0.1) 56(84) bytes of data.
> 64 bytes from 82.70.154.150: icmp_seq=1 ttl=255 time=1.08 ms
> 64 bytes from 82.70.154.150: icmp_seq=2 ttl=255 time=1.05 ms
> 
> xorpsh> ping 224.0.0.13
> PING 224.0.0.13 (224.0.0.13) 56(84) bytes of data.
> 64 bytes from 82.70.154.150: icmp_seq=1 ttl=255 time=1.07 ms
> 64 bytes from 82.70.154.150: icmp_seq=2 ttl=255 time=1.07 ms
> 
> xorpsh> show pim rps
> RP              Type      Pri Holdtime Timeout ActiveGroups GroupPrefix
> 
> (i.e. there are none)
> 
> Here is my configuration.
> /*
> <snip comments>
> */
> interfaces {
>     interface eth0 {
>         default-system-config
>     }
>     interface eth1 {
>         default-system-config
>     }
> }
> 
> plumbing {
>     mfea4 {
>         interface eth0 {
>             vif eth0 {
>                 disable: false
>             }
>         }
>         interface eth1 {
>             vif eth1 {
>                 disable: false
>             }
>         }
>         interface register_vif {
>             vif register_vif {
>                 disable: false
>             }
>         }
>     }
> }
> 
> protocols {
>     igmp {
>         interface eth0 {
>             vif eth0 {
>                 disable: false
>             }
>         }
>         interface eth1 {
>             vif eth1 {
>                 disable: false
>             }
>         }
>     }
> 
>     pimsm4 {
>         interface eth0 {
>             vif eth0 {
>                 disable: false
>             }
>         }
>         interface eth1 {
>             vif eth1 {
>                 disable: false
>             }
>         }
>         interface register_vif {
>             vif register_vif {
>                 disable: false
>             }
>         }
>     }
> 
>     fib2mrib {
>         disable: false
>     }
> }
> 
> Many thanks in advance,
> 
> Spencer
> 
> 
> _______________________________________________
> Xorp-users mailing list
> Xorp-users at xorp.org
> http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users



More information about the Xorp-users mailing list