[c-nsp] Need some ideas on trunking vlans over ATM

[Lamar Owen]

On Friday 25 April 2008, Steven Pfister wrote:
> I've got a situation where I have several (older) remote sites connected to
> a central site via ATM (they're being phased out for the most part). I need
> to find a way to have one particular vlan at each site assigned to a couple
> of ports on a switch at the central site. This only needs to be temporary
> and we only need one site's vlan to be active at a time (we're setting up
> new servers for each remote site, and it's necessary to have the new server
> in the site's vlan, and it's not convenient go actually go to each site).
>
> A typical setup is (starting at the remote site):
>
> core 3500 switch -> 3640 router -> 8510msr switch -> ATM cloud -> 8510msr
> switch -> 4507R central core switch
>
> I've noticed that the 8510s don't seem to understand vlans (no 'vlan' or
> 'vtp' commands). I'm assuming they'd need an IOS upgrade maybe, or should
> all versions do vlans?
>
> The ATM configuration was done before I got here, and I don't have much
> experience with it. I'm assuming that since IP connectivity seems fine
> between the sites, this should be do-able.

ATM can use Classical IP over ATM or LANE for ethernet/IP connectivity.  What 
NM is being used in the 3640?  Is this an OC3 interface, or ATM25?  what 
about the 4507?  

I have an 8510msr in production, within a Catalyst 5500 switch, and am using 
the Catalyst 5500's OC12 LANE card for the connecting interface.  VLAN's in 
the ethernet world map to ELAN's in the ATM/LANE world.  Kennedy Clark's 
Catalyst LAN Switching book from Cisco Press covers trunking over ATM 
thoroughly.

If you can send a 'sanitized' config from the 3640, 4507's ATM card, and the 
8510s, I may be able to help you.  The latest IOS on these beasts is a 12.1E 
train; I think they are up to 12.1(27)E, but I'm not sure.  They do not 
understand ethernet in any form, much less ISL or dot1q VLAN's, except for 
the management port (unless, that is, you have one with an ARM in it, and 
then you could mix ethernet and ATM in the same box, but even then the 
8500-series has no concept of VTP or similar Catalyst 'things'; they do have 
IRB, though).  I'm using 8540's in my core here; they were donated to us, and 
they are really really fast, but they are more like 12000's than Catalyst 
switches.

For an ELAN over LANE config, for each ELAN you need LECS database entries and 
an LES/BUS set up.  Just shooting off the cuff, my guess would be that the 
ATM card in the 4507 is set up as the LES/BUS for the ELAN's you have, and 
one or both of the 8510's is acting as primary and/or secondary LECS.

It depends on whether your setup is using LANE or CLIP as to how to add 
another VC for another VLAN.

For comparison, here's the relevant section of my sole 8510's config.  Note 
that I migrated away from an ATM/LANE core recently, and that the other 
switches were 3Com CoreBuilder 7000's, which is why my 8510 still has PNNI 
enabled, and has a 3Com-prefixed ATM address instead of a typical automatic 
Cisco one:

atm lecs-address-default 47.0079.0000.0000.0000.0000.0000.0000.a003.0000.01 1
atm address 47.0000.0000.003c.0000.a700.0000.0090.bf2e.f401.00
atm router pnni
 no aesa embedded-number left-justified
 node 1 level 72 lowest
  redistribute atm-static

I'm not running any of the LANE servers on the 8510, primarily because the 
Catalyst LANE cards are up to 50 times faster, especially for the BUS 
function.

Here's the 5500's OC12 LANE config (WS-X5162 card, slot 8).  I've included 
nearly the complete config:
pari-cr1-5500-1> session 8
Trying ATM-8...
Connected to ATM-8.
Escape character is '^]'.

cr1-5500-oc12sm-slot8>enable
password:
cr1-5500-oc12sm-slot8#sh runn
Building configuration...
[snip]
version 12.1
[snip]
hostname cr1-5500-oc12sm-slot8
!
lane database parilane
  name pari server-atm-address 47.00000000003C0000A7000000.0090BF2EF071.C0
  default-name pari
!
!
interface ATM0
 atm preferred phy A
 atm pvc 1 0 5 qsaal
 atm pvc 2 0 16 ilmi
 lane config fixed-config-atm-address
 lane config database parilane
 lane fixed-config-atm-address
!
interface ATM0.192 multipoint
 lane server-bus ethernet pari
 lane client ethernet 192 pari
!
!
line con 0
line vty 0 4
 no login
!
end

cr1-5500-oc12sm-slot8# 

Now, I don't have any routers with ATM interfaces connected by LANE at this 
point (I did have a 7507 with a couple of OC3 ATM cards, but that's not in 
service since I did away with the ATM core and am just using the ATM section 
to reach some outlying buildings on campus where the fiber length is too 
great for GigE, and where I already had ATM-connected switches; in 
particular, four 3Com Superstack II's with OC3 cards in them).  So I can't 
give you a sample LANE config for a router interface, sorry.

The hard part is determining all the ATM addresses you need.  The commands on 
the LANE card to get this:
cr1-5500-oc12sm-slot8#sh atm ilmi-status

Interface : ATM0 Interface Type : Private UNI (User-side)
ILMI VCC : (0, 16) ILMI Keepalive : Enabled/Down (5 Sec 4 Retries)
ILMI State:       UpAndNormal
Peer IP Addr:     192.168.1.25    Peer IF Name:     ATM11/1/0
Peer MaxVPIbits:  8               Peer MaxVCIbits:  14
Active Prefix(s) :
47.0000.0000.003c.0000.a700.0000
End-System Registered Address(s) :
47.0000.0000.003c.0000.a700.0000.0090.bf2e.f071.c0(Confirmed)
47.0000.0000.003c.0000.a700.0000.0090.bf2e.f072.c0(Confirmed)
47.0079.0000.0000.0000.0000.0000.00a0.3e00.0001.00(Confirmed)
47.0000.0000.003c.0000.a700.0000.0090.bf2e.f070.c0(Confirmed)
cr1-5500-oc12sm-slot8#  

ATM LANE is one convoluted puppy if you are new to it; I've done ATM here for 
5 years, and once you get you mind around some basic concepts it's not too 
hard.  Kennedy Clark's book 'Catalyst LAN Switching' as well as the Cisco 
Press book on ATM (I have it, but not right by my side at the moment) have 
excellent information on these things.

After purchasing the Clark book, I actually found the full text of it in PDF 
online.  It's also available on Safari. (safari.informit.com; subscription to 
this costs, but I find it to be worthwhile).

Hope that helps!
-- 
Lamar Owen
www.pari.edu