IP Address Assignment Question

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Good Morning Everyone,

I have a basic question regarding configuring a Cisco router.  It's an
1841.  Internet access is an MPLS T1.    Currently we have one static
IP address assigned to the internet facing FastEthernet interface and
I will be getting another 4 static IPs.  I have a firewall behind this
router.  I will be getting a Bomgar device for remote control
functions which will require an IP address and I have a monitoring box
which will also need an IP.

Am I correct in assuming that on my 1841 I would just create a static
route for each new external IP routing the traffic to the new devices
and then assign the actual IP to the end device?  Would any of these
IPs need to be assigned to the Cisco router?

On a more generic question, how many ip addresses can you assign to
one physical interface?



Re: IP Address Assignment Questiona.)
a.) your static route solution would work (other things being equal of
course), though if there are no other L3 devices in the way it you may be
able to get away with no extra routes on that WAN router if the subnet ends
up directly connected, remember to configure routes appropriately on any
routers in between + don't forget firewall rules and routes.

b.) two answers
subinterfaces - you can create subinterfaces (can't remember how many, but
its lots) and each can have different IP. Remember to configure trunking on
the switch facing it and create VLANs as appropriate. Your subinterfaces
will also need the correct trunking configs.

e.g. if your switch has VLAN10, VLAN20 and you configure a trunk going to
the router interface, the router interface config would be

interface Fa0/0
no ip address
interface Fa0/0.10
ip address x.x.x.x x.x.x.x
encapsulation dot1q 10
interface Fa0/0.20
ip address y.y.y.y. y.y.y.y
encapsulation dot1q 20
(repeat etc.)

physical interface - You can assign a secondary IP but it has to be in a
separate subnet. This is a legacy feature for the days before VLANs and
everybody used hubs, so you could have separate networks behind a single
LAN interface without using VLANs.

Metahugh wrote:

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