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how to get layer 2 trough layer 3 ?

 
 
C Cant
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      04-15-2005
hi ng,

how do i get layer 2 comunication trough layer 3?
i need to get cisco vlan information over a router. how do i do that? hints
tips suggestions, anything is welcome.
thank you colin


 
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Ivan Ostres
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      04-15-2005
In article <425f7b42$0$144$(E-Mail Removed)>,
http://www.velocityreviews.com/forums/(E-Mail Removed) says...
> hi ng,
>
> how do i get layer 2 comunication trough layer 3?
> i need to get cisco vlan information over a router. how do i do that? hints
> tips suggestions, anything is welcome.
>


You could use tunneling with GRE and bridging (not very smart solution)
or you could use one of the available methods like L2TP or AoMPLS,
depends on your use and if it it just one rotuer or a number of them.


--
-Ivan.

*** Use Rot13 to see my eMail address ***
 
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C Cant
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      04-15-2005
hi Ivan,

thank you for your help, its still all about my problem mentioned in the
"Fallback bedween a Laserlink and a HDSL modem line" post.

ok, could you give me some hints where to start wenn i dlike to push dot1q
traffic with your suggestions through this here
http://macant.home.solnet.ch/Laser.jpg

i think i have put a router there where my switches currently are, connect
it to the laser /modem and then connect each router to my building switch.
i'm still not getting this right.

> You could use tunneling with GRE and bridging (not very smart solution)
> or you could use one of the available methods like L2TP or AoMPLS,
> depends on your use and if it it just one rotuer or a number of them.



 
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C Cant
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      04-15-2005
how about taking two cat 3550 and use 802.1q tunneling on these tho
3550-SMIs in the middle witch are directly attached to the laser and the
modem. As decribed here
Updated version: http://macant.home.solnet.ch/Laser2.jpg
put the dot1q trunkport on the"edge" switches. then i just need a to give
the two 3550er in the middle for each line a own vlan and a management ip.
now via this management ips i could base my routing of that tunneling port.
and like this i could make sure the traffic gets over the interface witch
passes the traffic through. what kind of routing protocol could i use on a
3550er? if this should workout.



 
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Scooby
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      04-15-2005
"C Cant" <(E-Mail Removed)> wrote in message
news:425f7b42$0$144$(E-Mail Removed).. .
> hi ng,
>
> how do i get layer 2 comunication trough layer 3?
> i need to get cisco vlan information over a router. how do i do that?

hints
> tips suggestions, anything is welcome.
> thank you colin
>
>


May I ask why you want to do that? Perhaps there is a better solution to
what you are trying to do.


 
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C Cant
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      04-15-2005

> May I ask why you want to do that?


we got a vtp server in building A, and some departements in building B.
both buildings need the same vlan definitions. the buildings are connected
like the picture i put the link in the previous posts. now with fogy weather
we got some real problems. And for that reason we need a automatic failover
system. Spanntree does not workout for this, and so does etherchannel.

>Perhaps there is a better solution to what you are trying to do.

now, thats what im looking for

Picture:
http://macant.home.solnet.ch/Laser.jpg
http://macant.home.solnet.ch/Laser2.jpg



 
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Scooby
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      04-15-2005
"C Cant" <(E-Mail Removed)> wrote in message
news:425fd618$0$144$(E-Mail Removed).. .
>
> > May I ask why you want to do that?

>
> we got a vtp server in building A, and some departements in building B.
> both buildings need the same vlan definitions. the buildings are connected
> like the picture i put the link in the previous posts. now with fogy

weather
> we got some real problems. And for that reason we need a automatic

failover
> system. Spanntree does not workout for this, and so does etherchannel.
>
> >Perhaps there is a better solution to what you are trying to do.

> now, thats what im looking for
>
> Picture:
> http://macant.home.solnet.ch/Laser.jpg
> http://macant.home.solnet.ch/Laser2.jpg
>
>
>


Unless there is something very siginificant about your network setup that is
not reflected in the graphics, I still don't understand why you need the
same vlans in both locations. Each 3550 can be a vtp server for the
location it is at. Don't use vlans between them, use L3 and a routing
protocol. The routing protocol can be your failover. The end devices will
be on separate subnets. Or, is there a reason that both ends will need to
share a vlan/subnet? I'm not a fan of broadcasting over WAN links.

Jim


 
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Ivan Ostres
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      04-15-2005
In article <425fd618$0$144$(E-Mail Removed)>,
(E-Mail Removed) says...
> > May I ask why you want to do that?

>
> we got a vtp server in building A, and some departements in building B.
> both buildings need the same vlan definitions. the buildings are connected
> like the picture i put the link in the previous posts. now with fogy weather
> we got some real problems. And for that reason we need a automatic failover
> system. Spanntree does not workout for this, and so does etherchannel.
>


How often does your vlans change? How often do you delete or add vlans?
It is a common thing to disable vtp because it can do much more trouble
in networks than it makes administration easier.

I would still use L3 for laser and backup links and do the following:

If you need to have the same broadcast domains and still have routers in
between, why not try to use GRE tunnel for every VLAN and do a bridging
between VLAN and GRE? I've never tried it, but it might work (if I get
some time, I will try it)....

--
-Ivan.

*** Use Rot13 to see my eMail address ***
 
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C Cant
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      04-18-2005
>> still don't understand why you need the same vlans in both locations
we want to keep administration as little as possible. we get our vlan
definitions from the main building, vlans change pretty fast at our place,
so there is a lot of changes, and nobody likes to do the hole configs twice
or three times... there are several buildings attached the same way via
laser!

>> I'm not a fan of broadcasting over WAN links.

its about 250 up to 500 meters laser line

@ Ivan
>>If you need to have the same broadcast domains and still have routers in
>>between, why not try to use GRE tunnel for every VLAN and do a bridging
>>between VLAN and GRE? I've never tried it, but it might work (if I get
>>some time, I will try it)....

what do i need for this suggestion?

another question about spanntree, what happens if you build up two 3550er
connect each from fa0/1 to fa0/1 and fa0/2 to fa0/2. now each fa0/1 is in
vlan 10 and fa0/2 is in vlan20.
as vlan ip one would have a 192.168.10.2 the other .3
or of course for vlan 20 192.168.20.X
would spanntree block one side or would both sides be up? physical its a
loop, but since there are 2 diffrent vlans?
since i then would have a layer 3 ip on the other side would this then not
be posible to route it?




 
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Ivan Ostres
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      04-18-2005
In article <42637cb6$0$143$(E-Mail Removed)>,
(E-Mail Removed) says...
> @ Ivan
> >>If you need to have the same broadcast domains and still have routers in
> >>between, why not try to use GRE tunnel for every VLAN and do a bridging
> >>between VLAN and GRE? I've never tried it, but it might work (if I get
> >>some time, I will try it)....

> what do i need for this suggestion?
>
> another question about spanntree, what happens if you build up two 3550er
> connect each from fa0/1 to fa0/1 and fa0/2 to fa0/2. now each fa0/1 is in
> vlan 10 and fa0/2 is in vlan20.


That should work ok.

> as vlan ip one would have a 192.168.10.2 the other .3
> or of course for vlan 20 192.168.20.X
> would spanntree block one side or would both sides be up? physical its a
> loop, but since there are 2 diffrent vlans?


There would be two different spanning trees (if using PVST) so both
links should forward traffic.

> since i then would have a layer 3 ip on the other side would this then not
> be posible to route it?
>


IP address on vlan and physical interface are different things. You need
vlan 1 to push vtp between switches. This might get really complex. You
should probably search for some good consultant which has experience
with such setup.

--
-Ivan.

*** Use Rot13 to see my eMail address ***
 
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