[nsp] Bridging?

[Bruce Pinsky]

Vincent De Keyzer wrote:

> Douglas,
> 
> your efforts to understand my problem are remarkable and I highly appreciate
> them.
> 
> But I haven't been clear enough once again (I could say it's because english
> is not
> my mother language, but I am not sure I could do better in french... :) so
> let me
> try another way.
> 
> IP ranges:
> A.B.1.0/24: backbone ranges
> A.B.2.0/24: PtP (/30) ranges
> A.B.3.0/24: customer X range
> A.B.4.0/24: customer Y range
> 
> Current situation:
> * a 2621 with
> Fa0/0 = A.B.1.2/28
> Serial 0/0:0 = A.B.2.1/30 for customer X
> Serial 0/1:0 = A.B.2.5/30 for customer Y
> * customer X has a 1600+CSU/DSU with
> Serial0 = A.B.2.2/30
> Ethernet0 = A.B.3.1/24
> * customer X has a firewall with
> WAN = A.B.3.2/24
> * customer Y has a 1600+CSU/DSU with
> Serial0 = A.B.2.6/30
> Ethernet0 = A.B.4.1/24
> * customer Y has a firewall with
> WAN = A.B.4.2/24
> 
> The 2621 is routing IP packets between customer ranges A.B.3.0/24 and
> A.B.4.0/24 and the core network behind Fa0/0.
> 
> And, after replacing the (1600+CSU/DSU) by a E1/Eth bridge, I would like it
> to become:
> * a 2621 with
> Fa0/0 = A.B.1.2/28
> Whatever0 = A.B.3.1/24
> Whatever1 = A.B.4.1/24
> * customers X&Y have an E1/Eth bridge and their FWs keep the same config
> 
> ... where "Whatever" interfaces are whatever kind of interface it takes to
> have this working...
> 
> Now maybe this is now even called bridging... but is it possible?
> 
> The goal is of all this is to replace 1600+CSU/DSU by less expensive
> equipment where it's not required.
> 

Sounds like you want PPP half-bridging.   See: 
http://www.cisco.com/en/US/partner/products/sw/iosswrel/ps1831/products_configuration_guide_chapter09186a00800d9845.html#1001479

So at the customer site, you need an E1/Eth bridge that does PPP on the E1 
side.

-- 
=========
bep