connecting router to E1 line using CAB-X21MT cable

[lunarsystems]

Hello

I have a question about connecting the router to the E1 line, I have no knowledge/experience apart from CCNA.

I will connect a 1841 router with WIC-1T module to the E1 line using the X.21 DTE male cable.

What additional infomation will I need to have and what configuration will i have to do on the router in order to succefully setup the E1 connection to a remote site?

You can point me to the right documentation/tutorials on the web.

Thank you very much!

[jackyoung]

There is no special config. and just configure it as normal serial interface is fine.

The most important is to know the interface no., if you can't find it, you can type 'sh int" and it will show all interface w/ no.

Below is the doc.

http://www.cisco.com/en/US/products/hw/modules/ps3129/products_tech_note09186a00800b0859.shtml

Please feel free to let us know if there is any issue.

Hope this helps.

[lunarsystems]

Thanks for replying jackyoung.

I have other questions about the setup.

I have the router configuration, i.e. IP addressess for WAN links. The 1841 router will have a WAN interface private ip address and a router at the remote site will have a private WAN interface IP address.

Like this:

10.13.1.1/30 my site WAN interface IP address

10.13.1.2/30 remote site WAN interface IP address

10.3.1.3 LAN interface, my site

10.5.1.3 LAN interface, remote site

10.5.5.0 DHCP, remote site (255.255.0.0)

10.3.1.2 Default gateway, my site

The two routers are separated by a very large geographic distance. HDLC will be used.

The above is straight forward. However, a modem will be used for a dialing into the router and the router will have the WIC-1T module. Therefore, I presume that the modem will be used to dial in using the AUX port and the WIC-1T will be the WAN interface connected to a dedicated line such as the E1.

Would this be a reasonable assumption?

[globalnettech]

Hello,

in addition to Jack's post, the command 'show controllers' is also useful to verify that your X.21 DTE cable is connected correctly. When issued, the output of the serial interface tells you (I think in the second line) which cable is connected, e.g. 'X.21 DTE cable detected'.

As to your setup, it looks ok, just make sure that the default gateway for your clients on the 10.1.3.0 network is that of the IP address of the LAN interface. So, if your LAN interface has IP address 10.3.1.3, that should be the default gateway for your clients.

Regards,

GNT

[lunarsystems]

Thanks globalnettech!

So you mean that the default gateway with address 10.3.1.2 that was given to me is incorrect?

[lunarsystems]

The DHCP server I mentioned earlier (10.5.5.0), do I need to do anything about it when I am configuring the router?

[globalnettech]

Hello,

I am not sure why 10.1.3.2 has been given to you as the default gateway, but in any case, the default gateway for the clients needs to be the IP address of your LAN interface.

As with regard to the DHCP server: is the server also dishing out IP addresses for your 10.3.1.0 clients ? If so, you would need to configure an ip helper address on your LAN interface (the one with IP address 10.1.3.1), e.g.:

ip helper-address 10.5.5.2

if 10.5.5.2 is the IP address of your DHCP server.

Does that make sense ?

Regards,

GNT

[lunarsystems]

I'm not sure why I had been given the DHCP information and I have never used the ip helper-address command, but it looks straight forward.

Cheers for helping me out.

One last question though.

Since I'll be setting up a point to point link using the HDLC encapsulation, there is no use for a routing protocol, is there?