Point to Point T1

Dec 05, 2007 8 Replies

Hello:



I am trying to bridge to locations via a point to point t1. The provider says that they do no provide clocking on the line. My routers are 1720's with a WIC T1 interface card in both of them. Does anybody have a good configuration for this application? I would like to be able to pull DHCP from the main facility too. Is this possible? Currently I can ping the serial0 interfaces between the routers, but I cannot see through to the LAN. I am willing to scrap my current config, it somebody has a working config.



Thank you,



Jason Goddard


"John Smith" ha scritto nel messaggio news:BqGdnS7rx7BqUsvanZ2dnUVZ snipped-for-privacy@comcast.com...

Hi,

If the routers can ping each other then you are almost done; maybe you only need to configure some routing protocol betwen the routers or use static routes.

Regards, Gabriele

messaggionews:BqGdnS7rx7BqUsvanZ2dnUVZ snipped-for-privacy@comcast.com...

Thank you so much. Do you have an example of the static routes? Do I need to assign an ip address to my fastethernet0 ports? I mentioned above that I would like to DHCP over them, but now I am just going to plug my PBX's directly into them. So no need to DHCP. So basicily, I am creating a tunnel for two PBX's to talk back and forth.

Thank you, Jason

Hi,

If you just need static routing you only have to insert something like this (assuming 192.168.1.0/24 is reachable via router A and 192.168.2.0/24 via router B):

RouterA ip route 192.168.2.0 255.255.255.0 192.168.0.2 (where 192.168.0.2 is routerB serial interface address)

RouterB ip route 192.168.1.0 255.255.255.0 192.168.0.1 (where 192.168.0.1 is routerA serial interface address)

You can also avoid using an IP Address and use somethink like this (ip route ip route 192.168.2.0 255.255.255.0 serial

You need to assign an address to your fastethernet interfaces on both routers (this IP will be the gateway used by your IP PBX) (i.e.

192.168.1.254/24 for RouterA's fa0 and 192.168.2.254/24 for routerB's fa0)

to proxy DHCP requests arriving at an interface use something like this: ip helper-address

Regards, Gabriele

messaggionews: snipped-for-privacy@i29g2000prf.googlegroups.com...

Gabriele:

If I understand you correctly, I am plugging the ip address of my IP PBX's into the route table correct? My main pbx is 10.0.1.28

255.255.255.0. My main router serial interface is 10.0.0.1 255.255.255.252. My remote pbx is 10.0.1.30 255.255.255.0. My remote router serial interface is 10.0.0.2 255.255.255.252.

Is this correct?

Thank you for your patience I am almost there.

Jason

Hello john,

You should go for routing instead of bridging if possible.

I have not seen this on a E1 or T1 before. Read the article below to find out more on how to set some kind of clock.I am not sure if this is what you are looking for.

formatting link

Please post output of show diag from one of the 1720

messaggionews: snipped-for-privacy@i29g2000prf.googlegroups.com...

Hi,

You can't have two identical prefixes at both routers (without bridging, using NATor proxy ARP at least)... so, if you do not want to bridge, you have to use something like this

----------------------------------------------------------------- RouterA interface serial0 ip address 10.0.0.1 255.255.255.252

interface fa0 ip address 10.0.1.254 255.255.255.0

ip route 10.0.2.0 255.255.255.0 10.0.0.2

RouterB interface serial0 ip address 10.0.0.2 255.255.255.252

interface fa0 ip address 10.0.2.254 255.255.255.0

ip route 10.0.1.0 255.255.255.0 10.0.0.1

------------------------------------------------------------------

If you want (you shouldn't) you can used proxy ARP while having the same subnets on both routers (or better use bridging)

Regards, Gabriele

There is no clocking because its a point to point T1. I set one of these up recently. It was an AT&T provided line. One router provided teh clock, the other got it off the line.

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