[Xorp-users] multicast over GRE tunnel
Christian Lyra
lyra at pop-pr.rnp.br
Sat Feb 10 03:16:22 PST 2007
Hi there,
Just a message to let you know that the setup below just works. But
there was a few details missing. First when configuring the linux side
of tunnel I had to explicit set the TTL with the command ifconfig tun0
ttl 64. I took a while to found this... my firewall showed packets
coming in one interface but didnt leaving on the other! Second, I had
to disable rp_filter on xorp router! dont exactly know why. Btw there´s
a missing detail on my setup description. Xorp router has only one
ethernet card. It´s on the same net as desktops.
Thanks for listening (er... reading :-) ).
On Friday 09 February 2007 16:59, Pavlin Radoslavov wrote:
> Christian Lyra <lyra at pop-pr.rnp.br> wrote:
> > Hi there,
> >
> > I´d like to setup a xorp router to do multicast over a GRE
> > tunnel. My setup is like this:
> >
> > [multicast_enabled_net]----[Cisco-Router]---[no-multicast_net]--[x
> >orp_router]---[desktops]
> >
> > Between Cisco-router and xorp_router there´s a GRE tunnel so I
> > can trasverse the non_multicast_net. The protocol used is PIM-SM
> > and there ´s a "static" RP on multicast_enabled_net.
> >
> > I´m sure that all the other parts are ok, because I had a cisco
> > 2500 in the place of xorp_router and it work just fine with a
> > simple config like this one:
> >
> > ip multicast-routing
> > interface Tunnel1
> > ip address 200.x.x.154 255.255.255.252
> > ip pim sparse-mode
> > tunnel source 200.y.y.191
> > tunnel destination 200.y.y.9
> >
> > ip pim rp-address 200.z.z.z
> > ip mroute 0.0.0.0 0.0.0.0 tunnel0
> >
> > I tried to emulate this same configuration with xorp:
> >
> > xorp at teste# show
> > protocols {
> > igmp {
> > interface eth0 {
> > vif eth0 {
> > query-interval: 30
> > }
> > }
> > interface tun0 {
> > vif tun0 {
> > }
> > }
> > }
> > pimsm4 {
> > interface "register_vif" {
> > vif "register_vif" {
> > }
> > }
> > interface tun0 {
> > vif tun0 {
> > }
> > }
> > interface eth0 {
> > vif eth0 {
> > }
> > }
> > static-rps {
> > rp 200.z.z.z {
> > group-prefix 224.0.0.0/4 {
> > }
> > }
> > }
> > }
> > static {
> > route 0.0.0.0/0 {
> > next-hop: 200.x.x.x
> > }
> > mrib-route 0.0.0.0/0 {
> > next-hop: 200.x.x.153 /* tunnel */
> > }
> > }
> > }
> > fea {
> > unicast-forwarding4 {
> > }
> > }
> > interfaces {
> > interface eth0 {
> > vif eth0 {
> > address 200.x.x.191 {
> > prefix-length: 24
> > }
> > }
> > }
> > interface lo {
> > vif lo {
> > }
> > }
> > interface tun0 {
> > vif tun0 {
> > address 200.x.x.154 {
> > prefix-length: 30
> > multicast-capable: true
> > }
> > }
> > }
> > }
> > plumbing {
> > mfea4 {
> > interface eth0 {
> > vif eth0 {
> > }
> > }
> > interface "register_vif" {
> > vif "register_vif" {
> > }
> > }
> > interface tun0 {
> > vif tun0 {
> > }
> > }
> > }
> > }
> >
> >
> > One thing that I noticed is this:
> > xorp at teste> show pim neighbors
> > Interface DRpriority NeighborAddr V Mode Holdtime Timeout
> > tun0 1 200.x.x.153 2 Sparse 105 82
> >
> >
> > But Cisco doesnt see the xorp as a neighbor! (when using the
> > cisco 2500 instead of xorp, this Cisco router sees two neighbors,
> > one is the upstream one and the other the 2500).
> >
> > bb3#show ip pim neighbor
> > PIM Neighbor Table
> > Neighbor Interface Uptime/Expires Ver
> > DR Address
> > Prio/Mode
> > <wanip> FastEthernet1/1/0 04:14:05/00:01:39 v2 N /
> >
> >
> > Maybe I´m missing something.... or this can be compatibility
> > problem between xorp and cisco? Any clues? I can see the PIM join
> > messagens going out from tunnel interface.
> >
> > Btw... the xorp is running in a debian sarge. Kernel from distro,
> > and a little script to create the tun interface before the
> > xorp_rtmgr is started:
> >
> > ip tunnel add tun0 mode gre remote 200.ci.s.co local 200.lo.ca.l
> > dev eth0
> >
> > ifconfig tun0 allmulti
> > ifconfig tun0 multicast
>
> Your XORP configuration seems right. Well, you don't really need the
> "lo" interface configuration, but it shouldn't hurt as long as you
> don't touch it (e.g., reconfigure it).
>
> You mentioned that you see PIM Join messages going out from the
> tunnel interface. Do you see PIM Hello messages as well?
>
> If yes, could you check whether they have the IP Router Alert option
> set. This option shouldn't be set (it was specified in earlier
> drafts of the PIM-SM spec, but not anymore), and some (Cisco?)
> equipment might not like PIM control packets if the option is set.
> XORP-1.3 and earlier had the IP Router Alert option included, but
> this has been fixed in the latest XORP code in CVS.
> If you are running XORP-1.3 (or earlier), please get the latest code
> from anon CVS and see whether you still have the problem.
>
> Regards,
> Pavlin
>
> > --
> > Christian Lyra
> > POP-PR - RNP
> >
> > http://lyra.soueu.com.br
> >
> > ``The rules of programming are transitory; only Tao is eternal.
> > Therefore you must contemplate Tao before you receive
> > enlightenment.'' ``But how will I know when I have received
> > enlightenment?'' asked the novice.
> > ``Your program will then run correctly,'' replied the master.
> > The Tao Of Programing
> >
> > _______________________________________________
> > Xorp-users mailing list
> > Xorp-users at xorp.org
> > http://mailman.ICSI.Berkeley.EDU/mailman/listinfo/xorp-users
--
Christian Lyra
POP-PR - RNP
http://lyra.soueu.com.br
Thus spake the master programmer:
``After three days without programming, life becomes meaningless.''
The Tao Of Programing
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