Using 2 T1 for one default gateway

[ralwyn]

We have an existing network with full T1 running on Cisco 2600 series router point to point connection to our corporate office. My boss wanted to add another full T1 to the remote site for faster data transmission (for the Oracle database). I am not very familiar on having 2 T1 in one location and utilize both for one transmission. The corporate location will stay with one T1 and the remote site is the one that they wanted to add another T1. Should it be the other way around, since the server farm are located in the corporate location? My next question is how do I configure 2 T1 for one default gateway? Please help!

Thank you all in advance,
ralwyn

 

[sconde1]

Should be easy. Add the second T1 at the same location, it really does not matter, except for admin and maintenance. Create a second subinterface on the 2600 for the second T1. I assume you are using Frame Relay (?). Give the second line a new set of Ip's in a /30. Make a second ip route 0.0.0.0 to the same router and presto!.Provided you use a routing protocol such as eigrp, and both T1's are full T's (1544Mbps), same bandwidth, eigrp will use both as active and load balance 50/50. I actually use traditional T1's (4 pair) and a DSL T1 both with Frame Relay, and works as a charm without any further config!

Also, look on the subject of "bonding T1's".

Finally, check your pricing with your vendor. I found great pricing for a fractional T3 instead of a second T1. You can get 3 megs to get started, but can upgrade anytime,doubling the bandwidth up to the full T3 (45 Megs) just calling the provider... Your 2600 suports T3. Of course this does away with redundancy, but unless you get different vendors and use different co's, a second one will go down with the first one usually.

Good Luck!

 

[ralwyn]

Hello sconde1:
Thanks for quick response. I will try and configure what you have provided. Our 2nd T1 should be in place in the next 3 weeks. Adding sub-int should be easy enough for both ends and add ip route. Thanks again, and I will update the result.

 

[webnetwiz]

Also check out MPPP (Multilink Point to Point Protocol), it lets u bundle multiple links.

 

[rainman]

Yes MLPPP is a great solution. You can add/delete serial interfaces to the multilink bundle as needed and get your load balancing / redundancy. Easy to configure also.


-Rainman

 

[ralwyn]

Thanks webnetwiz and rainman I will consider all options.

-ralwyn

 

[NetEng631]

If you are using point to point Serial T1's using HDLC you do not need sub interfaces. You also do not need MLPPP. If you running a routing protocol like OSPF the links will automatically load balnce. You do need another /30 address. So link one will be it's own /30 network and link 2 will be it's own /30 network.

NetEng

 

[ralwyn]

NetEng631:

Thanks! We are running eigrp as our routing protocol. Is there a link that you can provide? Again, thanks.

-ralwyn

 

[3wsparky]

sconde1 do you have a config you could post of your success

would like to see whats involved

many thanks

Terry