Question about feasibility in using a C2960 24TT-L for a very special situation

essax_ltd · ‎06-10-2013

I'm fairly new to Cisco products and IOS and therefore I would need help to figure out if the following

situation could be solved in using a C2960 24TT-L ( with c2960-lanbasek9-mz.150-2.SE2)

and if so, what would be the commands to configure.

We are testing in our test lab special devices and such a device has one ethernet interface,

configured by firmware, with 4 IP addresses (192.168.255.1,192.168.255.33, 192.168.255.34

and 192.168.255.35) and gateway address 192.168.255.126.

Now the idea is to link 20 of such devices to the C2960 and assigning to the gigabitEthernet port

routed/NATed IP addresses, as example:

fa port 1: 192.168.255.1 <-> 10.47.187.10

fa port 1: 192.168.255.33 <-> 10.47.187.11

fa port 1: 192.168.255.34 <-> 10.47.187.12

fa port 1: 192.168.255.35 <-> 10.47.187.13

fa port 2: 192.168.255.1 <-> 10.47.187.14

fa port 2: 192.168.255.33 <-> 10.47.187.15

fa port 2: 192.168.255.34 <-> 10.47.187.16

fa port 2: 192.168.255.35 <-> 10.47.187.17

and so on.

We can choose the IP,s for the gigabitEthernet port but the device IP's are fixed.

I know that this is not the typical situation for such a product like the C2960

but would simplify our test lab management and so I'm asking if someone can

tell me if this would feasible in using our C2960.

Thanks in advance.

Jeff Van Houten · ‎06-10-2013

NAT occurs at a layer 3 boundary. The 2960 is a layer 2 device. The switch can't create NATs.

Sent from Cisco Technical Support iPad App

essax_ltd · ‎06-10-2013

Thank You for Your answer.

Hmm, but it's interessting becuase according to

http://www.cisco.com/en/US/docs/switches/lan/catalyst2960/software/release/12.2_55_se/configuration/guide/swipstatrout.html

it has L3 cababilities with 12.2_55 or newer, but You are right, seems to be without NAT support and without

it might be not feasable.

But at least it can route:

Switch#show sdm prefer

The current template is "lanbase-routing" template.

The selected template optimizes the resources in

the switch to support this level of features for

0 routed interfaces and 255 VLANs.

number of unicast mac addresses: 4K

number of IPv4 IGMP groups + multicast routes: 0.25K

number of IPv4 unicast routes: 4.25K

number of directly-connected IPv4 hosts: 4K

number of indirect IPv4 routes: 0.25K

number of IPv6 multicast groups: 0.375k

number of directly-connected IPv6 addresses: 0.75K

number of indirect IPv6 unicast routes: 0.5K

number of IPv4 policy based routing aces: 0

number of IPv4/MAC qos aces: 0.125k

number of IPv4/MAC security aces: 0.375k

number of IPv6 policy based routing aces: 0

number of IPv6 qos aces: 0.375k

number of IPv6 security aces: 127

paolo bevilacqua · ‎06-10-2013

http://www.cisco.com/en/US/docs/switches/lan/catalyst2960/software/release/12.2_55_se/configuration/guide/swipstatrout.html

it has L3 cababilities with 12.2_55 or newer, but You are right, seems to be without NAT support and without

it might be not feasable.

Is is not that "it seems". As correctly mentioned above already, access switches do not do NAT. For that, you need a router.

Also, do not realy on these switching for routing, as that is not what thye have been designed for.

essax_ltd · ‎06-11-2013

Good morning,

In general You are right, we just thought we could use it for that purpose because we

have several laying around and due the announcement that with a newer IOS it's cabale

to route.

Regards

Wolf

Wilson Bonilla · ‎06-10-2013

Good morning:

It's documented, catalyst fixed and 4ks do not support NAT.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a008011c629.shtml

Regards.

Wilson B

essax_ltd · ‎06-11-2013

Good morning,

Sorry but I couldn't find the 2960 in that document.

Regards

Wolf