The Cisco
3750 range has been around for many years now, and has a vast
following. The Cisco 3750-X is the new kid on the Cisco block, and it combines
plenty of stuff that will be familiar to users of its predecessors with some
funky new features that are clearly a step forward.
Cisco 3750 switch comes in a number of
flavors – between 24 and 48 ports, with or without Power over Ethernet. Cisco
3750 with 48Pis the PoE variant of the 48-port device. Now, the traditional
Cisco 3750 had four 1Gbit/s SFP ports in addition to the 48 10/100/1000 copper
ports; the Cisco 3750-X instead has a slot into which you can slot either a four-port
1Gbit/s SFP daughter-board or a two-port 10Gbit/s alternative.
Alongside the port combinations, there are
three software installs. The LAN Base software is a layer-2 only software
image, and quite frankly I wouldn't ever expect to buy one of these if I only
wanted layer-2 functionality. More sensible is the IP Base image which makes
the device a proper Layer-3 routing switch, albeit with a limited selection of
routing protocols. At the top is the IP Services image, which makes the unit a
full-blown router (just like its ancestors – two of my BGP-shouting WAN routers
are actually 3750Gs, in fact). The main market will of course be for the IP
Base version.
The rear panel is interesting too, of
course. As with the older 3750s the rear panel has a pair of “stack” ports.
Each stack port provides a 16Gbit/s backplane connection, and by stacking your
devices in a loop you end up with a resilient 32Gbit/s backplane. From a
management and configuration point of view a stack is a single virtual switch –
you manage it rather like a chassis product with a number of blades. So port 1
of switch 1 is Gi1/0/1, port 3 of switch 2 is Gi2/0/3, and so on.
The important rear-panel innovation with
the new CISCO 3750-X model is the provision for redundant power supplies. In
the old model you had a single, non-removable power supply along with an RPS
(Redundant Power Supply) connection; to use the latter and give yourself some
resilience you had to buy something like an RPS2300 – an external device that
was a stupid shape that didn't fit into a rack very well, had buttons on the
front whose only purpose seemed to be to make things break, and on a brighter
note provided up to six switches with resilient power. The new model has dual
slots for removable PSUs, of which one is populated by default; it's a
ten-second job to slip a second one in beside it. One of the downsides of the
old 3750 was the bloody awful reliability of the internal (fixed) PSU, and I've
spent rather too many hours swapping out units with duff power units, so the
removable units in the -X are most welcome.
Along with the redundant PSU facility is
the power stacking capability. Just as you have your data stack cables, you
also now have a pair of power-stack cables on each unit, so that the total
power available via all the PSUs in the stack is available for negotiated use
across the whole stack, for switch power and PoE.
As with the older devices, you can add and
remove stack devices on the fly. Adding a switch to a stack is a simple case of
settings its ID, telling the stack to expect a new member, and plumbing it in
(although in theory the stack will deal with firmware mismatches in the new
member, I prefer not to tempt fate so I always pre-install the right version).
If a unit fails the stack will keep on humming while you pull out the duff one
and stick in the replacement, and the config will be automatically migrated to
the new unit.
The only downside I've found so far, in
fact, is with trying to get the new -X model to co-exist in a stack with the
old 3750-G (in short, I've not persuaded it to actually work yet) but I've no doubt I'll
persuade it to play before long.
The Cisco 3750-X is a really sensible
evolution in an already popular family of switches in the Cisco family. Being
an IOS device there's really not a great deal of difference management-wise
between the old and the new, so you get new functionality with almost zero
additional training requirements. I've recently added seven 48-port non-PoE
versions in three of my server installations, and have just received two new
pairs of the PoE variant in a couple of offices, and I'm pretty happy thus far.
Pro
New power stacking capability is an
excellent evolution.
32Gbit/s backplane should be sufficient for
most modest installations.
10Gbit/s Ethernet support for uplinking or
connecting to blade servers.
Sample Pricing for Popular Cisco
3750 Models:
Catalyst 3750X 24 Port Data LAN Base: US$2,236.00(57.00%
off list price)
Catalyst 3750X 48 Port Data LAN Base: US$3,827.00(57.00%
off list price)
Catalyst 3750X 24 Port Data IP Base: US$2,795.00(57.00%
off list price)
Catalyst 3750X 48 Port Data IP Base: US$4,945.00(57.00%
off list price)
Catalyst 3750X 24 Port PoE IP Base: US$3,139.00(57.00%
off list price)
WS-C3750X-48P-S: Stackable 48 10/100/1000
Ethernet PoE+ ports, with 715W AC Power Supply: US$5,590.00(57.00% off list
price)
Supplier
Router-switch.com ((Yejian Technologies
Co., Ltd), a World's Leading Cisco Supplier
