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Cisco 3620 Sub Interfaces / NAT

I am looking for some assistance in creating some
sub Interfaces and NAT on a CISCO 3620.


Here is what I am looking at doing.


Int 0/0.1  - 219.210.117.1 /25 (NO Nat)
Int 0/0.2  - 172.28.10.1   /23 (NAT Masquerade)
Int 0/0.3  - 172.28.12.1   /24 (NAT Masquerade)
Serial 0/0 - 219.63.168.10 /30

Default Route to 219.63.168.9 (via Serial 0/0)


I want Each Sub-Interface to be able to route to
the other sub interfaces and all to route to a the
internet via Serial 0/0 (T1 CSU/DSU).

I am running Cisco IOS ver 12.1(5)  and will be upgrading
to '12.3(5)' in the next couple of days.


Thanks for any help.

Mark Anderson

0
networkfrontier
Asked:
networkfrontier
  • 2
1 Solution
 
lrmooreCommented:
That's pretty easy if you want to nat  everything to the serial 0/0 interface address

interface serial 0/0
 ip nat outside
!
interface ethernet 0/0.1
 ip address 219.210.117.1 255.255.255.192

!
interface ethernet 0/0.2
 ip address 172.28.10.1 255.255.255.0
 ip nat inside
!
interface ethernet 0/0.3
 ip address 172.28.12.1 255.255.255.0
 ip nat inside
!
!
access-list 2 permit 172.28.10.0 0.0.0.255
access-list 2 permit 172.28.12.0 0.0.0.255
!
ip nat inside source list 2 interface serial0/0 overload
!

That's about all you have to do for simple nat

0
 
networkfrontierAuthor Commented:
lrmoore,

When I try this  I get :

% Configuring IP routing on a LAN subinterface is only allowed if that
subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q,
or ISL vLAN.

How do I get around this?

Mark Anderson
0
 
lrmooreCommented:
Assuming that your switch is using dot1Q vlan tagging:

interface ethernet 0/0.2
 encapsulation dot1Q 2  <-- VLAN #
 ip address 219.210.117.1 255.255.255.192

interface ethernet 0/0.3
 encapsulation dot1Q 3  <-- VLAN #
 ip address 219.210.117.1 255.255.255.192
!

Etc...
I was not sure if you were doing VLAN Ethernet sub-interfaces or serial sub-interfaces like on a frame-relay wan..


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