How to connect 2 LANs on same subnet

[vishanv]

Out of curiosity, just to better my knowledge, how can I connect to LANs that are remote from each other using a leased line and still have them in the same network & subnet.

Example siteA 10.0.0.0/8 and siteB 10.1.0.0/8

What devices will I need ?

[t.baranski]

Bi-directional NAT does the trick, though it's ugly. See http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f30.shtml

[peterbe]

You need to bridge between the two sites (layer 2). Remember that all your broadcasts will also go across the leased line.

A Cisco router can bridge.

Let me know if you need sample config.

[vishanv]

pete,

I would be grateful if you could post the sample config. Its OK, I can live with the broadcasts.

[peterbe]

I have not tested the config below but it should provide a starting point. '...' is the usual interface configuration. Hope it helps.

bridge irb

!

interface Loopback0

ip address 10.....

...

!

interface FastEthernet0/0

no ip address

bridge-group 1

.....

!

interface Serial0/0

no ip address

bridge-group 1

....

!

interface BVI1

ip address 10....

[bbravo]

Do you know of any issues regarding bridging and utilization on the WAN interface, in my case I have 2 3640's (hssi and ATM) over a DS3, but the utilization on both interfaces never goes above 40 %, even when transferring large amounts of data, do you have any idea why, I really appreciate your help, this has been bothering me for a while, thanks again!

[t.baranski]

An issue that commonly pops up with high-bandwidth circuits involves TCP itself. Have a look at http://www.faqs.org/rfcs/rfc1323.html for information on why, depending on the TCP configuration of the end hosts, a single TCP stream may not be able to saturate a high-bandwidth WAN connection.