I have not tried this with Dynamips. This might very well be a Dynamips issue. I have only tried this with real equipment and it worked fine.
So if you didn't set the system MTU on your switches to 1504 and reload, make sure you do that to account for the extra 4 bytes of encapsulation.
When you sniff the traffic with SPAN, are you using the encapsulation replicate keyword in your configuration? By default the SPAN session will relicate all frames as untagged packets to the SPAN destination port. In order to see the dot1q tag, you will need to use the encapsulation replicate keyword.
As a side note, you should tag your native VLAN traffic and make sure that the provider native VLAN doesn't match customer native VLAN.
I know there a some folks on CLN that have a similar set up. Maybe they can give it a test run for you.
hey, thanks for the thoughts. Ah I think I got caught out with span there. I was doing it on a 2950 and I dont think it has the replicate feature. I will try it on my 3750 and see what the results are.
I will have another go and set all switches to 1504 and reload and see what happens. If anyone has any other ideas id love to hear of working setups.
I shall report back if I get this to work.
It does work on gns3. With gns3, i find that you have to start all routers up before entering any config, or you have buggy interfaces. Here is what i did:
Nice blog post there! very informative. How would you go about doing that in dynamips?
Would you make cpe1.3560 and cpe2.3560 a router in gns3 with subinterfaces running dot1q and trunk it to each of the virgin edge switches?. I have tried doing that but to no avail. It is all good but I guess just having proof of concept is nice but not to worry.
Hmm, when I did it in gns3 you have to add a switchport module so that the router can be a switch as well. If you add a router, right click > configure > click on the hostname > slots tab > slot 1 > NM-16ESW.
Then connect each of the routers together using only the ports from that module (which for me is usually anything begining f1/0 or above. The routed ports are usually fa0/0 or fa0/1 (dont use these). If you need to make a routed port using the switchport module, just use #no switchport on the interface.
Ok so I have solved my problem. It is not a bug with dynamips at all. It was a bug with me trying to do some crazy stuff.
I got another 2 NIC's for my pc so I could use the one dynamips process. Basically what I was doing before was I had my laptop running dynamips in windows then on my linux box I had dynamips running on that also. ( I tested that this does work but only if you want to do basic pings on the same vlan with windows firewall disabled but qinq stuff never worked. )
So now I have R1 and R2 running on the same machine on seperate nics.
connectivty is 100% between R1 and R2 now.
The thing is I have a SPAN session setup on my 3750 but I only see the 1 vlan tag for vlan 30. I am not sure how accurate span is but I did do encapsulation replicate.
I am confident qinq is working as it should as a ping from R1 to R2 with a size of 1497 or higher is failing but 1496 works proving that the extra metro tag of 101 is being added
So my advice is create your virtual dynamips topology on 1 computer and map everything to your NIC's on that same computer. Dont mix and match!
After a week of stuffing around I am happy I got this to work now
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