[tech] New UWA network interface options

David Adam zanchey at ucc.gu.uwa.edu.au
Mon Oct 17 21:09:13 WST 2011


UWA is getting an exciting new core network, which promises to be 
highly-buzzword compliant. UCC is one of the test groups for the new core 
network, mostly because apparently we're one of the few groups on campus 
doing actual service over IPv6.

To interface with the new network (which will be gigabit fibre to the 
Cameron Hall comms room), we need to upgrade our current uplink equipment 
in the Cameron Hall comms room, which is currently simply a 100mbit fibre 
convertor.

There are two options immediately available:

- Install sesame, a Cisco Catalyst 3508G XL donated by [AHC] and 
  refurbished by me; this has 8 GBIC slots and is currently configured for 
  dual 1000baseLX (single-mode fibre) and 1000baseTX (copper).

- Install palm, a Cisco Catalyst 2948G-GE-TX with 48 10/100/1000baseTX
  ports and 4 SFP slots (the Uni will lend us SFPs on a long-term basis).

The problem with the first option, which I discovered with a trill of gay 
laughter after having spent many hours trying to get it working, is that 
you can't connected any 100 megabit devices to a copper GBIC. However, I'm 
not convinced that our uplink copper cable will support gigabit traffic. 
Also I will ask the club for $50 to recoup part of the cost of new fans 
and GBICs. [*]

The problem with the second option is that it takes what is currently our 
LAN switch out of commission and wastes 44 perfectly good copper ports. 
However, with the new giant Cisco 4507R installed in the rack, we might be 
migrating off coconut (same model as palm) sometime soon anyway, which 
would negate this.

Alternatively, if we can talk [AHC] into selling or donating the Cisco 
2948G living in the machine room (which has 48 10/100 ports but two GBIC 
slots), we could use that if our uplink doesn't support Gigabit speeds.

Opinions and other alternatives welcome. UWA IS (nee ITS nee UCS) has 
stipulated against the use of media converters and is very keen to have 
everything that interfaces with the core network from the Cisco line. 
Replacing the uplink copper to the Cameron Hall comms room is apparently 
prohibitively expensive.

David Adam
UCC Wheel Member
zanchey at ucc.gu.uwa.edu.au

[*]: it also doesn't support PAgP/LACP or load-balancing over aggregation 
groups using anything other than level 2 addresses. We only have two level 
2 address doing any real work on that link, but that's largely irrelevant 
because our bottleneck is the piece of copper between the Cameron Hall 
comms room and the UCC machine room.


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