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Point to Point T1 utilizing DHCP Cisco 1700 series / 1600 series

I have a ptp T1 that goes from Location A to B.  Location A has a 1600 series, and B has a 1700 series router.  Both have Cisco DSU's.  The Main network is at Location A.  The network there is 198.42.170.X with a subnet of 255.255.255.128.  I have enough open IP's on this node to assign them over the T1.  How do I configure the Routers so that the DNS/DHCP server at the main location will be able to serve location B?

I reloaded both of the routers from scratch then entered the following config.

config t
bridge 1 protocol ieee

int s0
ip address 198.42.170.4 255.255.255.128
encapsulation PPP
No Shutdown
bridge-group 1

EXIT

int fastethernet0
no shutdown
bridge-group 1

exit

no ip routing

exit

What am I missing here?  Do I need to seperate the routers from the network at location A?  Do I need to configure the FE ints with the range/subnet of network A, while creating a different .x network between the two routers on the serial
Avatar of cycle303
cycle303

First of all you will need to create a network between the two devices.  EX
network A -- ptp network -- network B
Then you will need to sync the two with these commands.  
Network A
service-module t1 clock source line
Network B
service-module t1 clock source internal
Start here first..
Avatar of leemae85

ASKER

Is it not possible to have it be Network A at both ends?

I didn't enter in the service-module t1 clock source line because in the newer versions of IOS it is activated by default.
What you are asking is pretty simple

RouterA                        
--------                      
Interface ethernet 0
 bridge-group 1
Interface serial 0              
 bridge-group 1

bridge 1 protocol ieee

RouterB
--------
Interface ethernet 0
 bridge-group 1

Interface serial 0
 bridge-group 1

bridge 1 protocol ieee

Since this is a point to point t1 you will need to configure the clock source on each serial interface. Most providers do not provide this on point to point links.

I would recommend that you NOT bridge the networks. This is going to put all your broadcast traffic over the wan and I expect that you will see pretty poor performance. It's much better to use routing in this scenario.

Hope this helps
B
Oops,

Forgot to mention that you probably want to create a loopback inter face on each router and assign it an ip address for management purposes

Router>enable
Password:
Router#Config t
Router(config)#interface loopback0
Router(config-if)#ip address xxx.xxx.xxx.xxx
Router(config-if)#end
Router# wr mem

Hope this helps
B
B,

So otherwise the configuration I currently posted however, add the ip address of each router under config-if?

ergo, if internal ip were 192.168.1.5 on Router A I would

config t
interface loopback0
ip address 192.168.1.5 255.255.255.128
ctrl^Z
wr mem

In addition can you kind of walk me through a little bit more?

I was having the clock source set as internal on both routers..is this incorrect?

I assume with this loopback command then it negates the need to enter in the ip on the serial interface?
In addition, were I not to bridge the connections..how would I configure it so that the clients would still be able to resolve local IP's over the PtP and the DNS server etc.  The PtP is providing not only a network connection from a-b but also internet connectivity.  Can you help me out with this solution if this is the one that you would more reccomend?  At which point I would assume at the B location I would need to use Router B as the gateway?
On you first reply,
Yes but drop the ppp and ip address on the serial interface.
For timing you need one set to line and the other internal.

on the second reply,

It depends on the number of clients and ip addresses needed at each site. DNS and local name resolution is pretty easy to configure but we would need a more detailed description of the environment and equipment involved. A network diagram would be great.

B
Network A is the core network.

There is a T1 (internet connection) comingin on a 1720 there, which then goes into firewall, and into the switch.  I have one DNS/DHCP server at that location and the location is set up on a .128 subnet mask.  there are enough addresses for this small branch left to be given out.  At the other location I simply just have a router, and client computers.

T1---1720----Switch----1600--PtP---1720---B(client computers)
                        |
          DNS/DHCP server/LAN

Would it be so detestable to try and bridge then?
In addition I am getting a carrier detect light at location B, but I am only getting an orange alarm at Location A (on the DSU/CSU Wic's).

The telco said that the circuit was complete, and they could see equipment at one end, but not at the other.  (The one end being location B)
Check your cabling and make sure the interface isn't shutdown.

You can set up the bridge and then see if you have problems with speed, if you do then go to a routed network.
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leemae85
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