How to loadshare over many E1 links

Fri Sep 18 15:54:03 UTC 1998

Try making the routes across the links doubly-recursive.  I don't know
how well this works, but it is worth a try.  For example:

RTRA-Loopback0 IP 10.1.0.1/30
RTRA-Loopback1 IP 10.1.1.1/30
RTRA-Loopback11 IP 10.1.11.1/30
RTRB-Loopback1 IP 10.2.0.2/30
RTRB-Loopback1 IP 10.2.1.2/30
RTRB-Loopback1 IP 10.2.11.2/30

Then route to one loopback over 4-6 E1's and the other over the other
4-6 E1s

Then, route the Loopback 11s over the two loopbacks.  Again, I don't
know if this would work, but it just popped into my head.

Example Config
RTRA
int loopback 0
 ip address 10.1.0.1 255.255.255.252
!
int loopback 1
 ip address 10.1.1.1 255.255.255.252
!
int loopback 11
 ip address 10.1.11.1 255.255.255.252
!
int s0
 ip address 192.168.0.1 255.255.255.252
!
int s1
 ip address 192.168.1.1 255.255.255.252
!
<snip>
int s11
 ip address 192.168.11.1 255.255.255.252
<snip>
! The first 6 E1s
ip route 10.2.0.0 255.255.255.252 192.168.0.2
ip route 10.2.0.0 255.255.255.252 192.168.1.2
ip route 10.2.0.0 255.255.255.252 192.168.2.2
ip route 10.2.0.0 255.255.255.252 192.168.3.2
ip route 10.2.0.0 255.255.255.252 192.168.4.2
ip route 10.2.0.0 255.255.255.252 192.168.5.2
! The other E1s
ip route 10.2.1.0 255.255.255.252 192.168.10.2
ip route 10.2.1.0 255.255.255.252 192.168.11.2
ip route 10.2.1.0 255.255.255.252 192.168.12.2
ip route 10.2.1.0 255.255.255.252 192.168.13.2
ip route 10.2.1.0 255.255.255.252 192.168.14.2
ip route 10.2.1.0 255.255.255.252 192.168.15.2
!
ip route 10.2.11.0 255.255.255.252 10.2.0.2
ip route 10.2.11.0 255.255.255.252 10.2.1.2
!
ip route 172.16.16.0 255.240.0.0 null 0
!
router bgp 65555
 neighbor 10.2.11.2 remote-as 65554
 network 172.16.16.0 mask 255.240.0.0

Of course, you may have to process-switch the packets, or use CEF, which
you mentioned.

-Chris

> -----Original Message-----
> From: Jesper Skriver [mailto:jesper at skriver.dk]
> Sent: Friday, September 18, 1998 3:57 AM
> To: nanog at merit.edu
> Cc: tdk-backbone at t.dk
> Subject: How to loadshare over many E1 links
> 
> 
> Hi,
> 
> How would you loadshare over many (>6) parallel E1 links. Currently we
> do it by connecting them directly to the Cisco's in each end, and do
> CEF based per-packet loadsharing, it works fine, but support a max of
> 6 E1's ...
> 
> I've been thinking om something similar to the Larscom inverse MUX
> (http://www.larscom.com/t3ft3/t3_megae.htm), but this one only support
> 4 E1's, then I can use multiple i-mux's and loadshare over 
> the 8M links
> they provide, but it seems like a poor solution.
> 
> Yes, I do know that a E3 would be a far better choice, but our ADM 
> (Add-Drop-Multiplexer??) at this specific location only support
> E1's :-(
> 
> /Jesper
> 
> -- 
> Jesper Skriver (JS249-RIPE), Network manager      
> Tele Danmark DataNet, IP section (AS3292)
> 
> One Unix to rule them all, One Resolver to find them,
> One IP to bring them all and in the zone to bind them.
> 