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Help in Setting up Cisco 2811 serial Leased Line connection.


Hello to all,

I would like to mention that I am a total new comer (NOOB) for Cisco Router. All I know is plug the console cable to a serial port on a PC, fire-up HyperTerminal to view and that's it. I don't know any command or scripts.

I am trying to lend a hand to my client to help him setup his connection, I already receive the required configuration settings from ISP. It is a Leased Line Serial connection.

Could some of the gurus here teach me how to setup the router with the below configuration.

Serial IP : 1.X.XX.222

Serial Netmask : 255.255.255.XXX

LAN IP : 1.X.XXX.1 to 1.X.XXX.31

LAN Netmask : 255.255.255.XXX

Default gateway (IP Route) : 1.X.XX.221

Encapsulation : PPP

DNS Servers to point to : XXX.XXX.0.136 & XXX.XXX.1.5

(DQ) is 14602975 & 14602974

Thank you,



5 Replies 5

Tod Larson

What sort of serial leased line?   T1?

Is the serial line an internet link or a link to another site on a private network?

Can you do a show run then cut paste the config you have into this thread?

Reza Sharifi
Hall of Fame Master Hall of Fame Master
Hall of Fame Master

Hi Andrew,

You need to configure the IP address for each interface, but before you do that you need to figure out which LAN and WAN interfaces are in up and up mode.

So, once you login to the router issue this command to fiure out the interfaces":

"sh ip int bri" and post it here

also do a "sh run" and post the output here



hi andrew,

could you post your show version output? how many serial links are you going to terminate on your 2811? i've noticed you've got 2 circuit IDs (DQ xxx).

Hi Guys,

Thanks for the prompt reply, Tod, John, for your information, it is a Internet Connection Direct over Leased Line, and yes, there are 2 serial links because its a 2Mbps x 2 connection into the 2811 router.

hi andrew,

thanks for confirming! kindly post your show version and show ip interface brief output.

as for the config on your 2811 obtain the /30 WAN IP address for the 2 serial links from your ISP and try to do as below:

ip name-server XXX.XXX.0.136

ip name-server XXX.XXX.1.5

interface serial x

description DQ 14602974

ip address a.a.a.a

encapsulation ppp

ppp multilink

multilink-group 1

interface serial y

description DQ 14602975

ip address b.b.b.b

encapsulation ppp

ppp multilink

multilink-group 1

interface multilink1

ip address 1.X.XX.222

ppp multilink

multilink-group 1

interface fast 0/0

ip address 1.X.XXX.1 255.255.255.XXX

ip route 1.X.XX.221

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