Help With Aggregating 2 HDLC Serial Links

[Domwilko_2]

Could someone give me some help with configuring 2 HDLC serial links for aggregation?

Here is the scenario:

2 x 3640 routers with 1 x NM-4T modules in each.

Serial 2/0 on router 1 is connected to serial 2/0 on router 2 - bandwidth is 512K

Serial 2/1 on router 1 is connected to serial 2/1 on router 2 - bandwidth is 512K

All I want to do is aggregate the two 512k (point-to-point HDLC) serial links so that they give me 1 x 1mbps link.

I'm sure this is not difficult, but I have never done it before and I can't seem to find any examples elsewhere on the Cisco.com web site.

Thanks in advance.

[lgijssel]

What are these links connected to?

When they have the same destination, and they advertise with the same metric, load-balancing will be done automatically.

When both links connect to Internet, but through different ISPs, applying load-balancing is not advisable. In that case you will receive better results when you route to a link on a per-session basis.

Regards,

Leo

[Domwilko_2]

Both links terminate on the same router at both ends, but we are using static routing from the 'outside' networks on each router. Do we need to use a dynamic routing protocol across the links or is it still possible using statics?

Thanks,

Dominic

[vincent-n]

It's not possible to aggregate 2 x HDLC links together. You'll have to use other encapsulation such as PPP since this L2 protocol has the ability to aggregate links together (this is built into the protocol). If you still want to use HDLC then simply follow the previous posting.