nat uturn or pbr loopback?

Fotiosmark · ‎03-26-2018

Hello team, I know this is a topic that is very much discussed, but it is simple killing me!!!!

There are 2 sites, 1 with Cisco router 18xx and one with a Vigor3200. one site has teh 192.168.1.0/24 and the other 9.0/24 as internal IPs!

Now, for SOME reason on the Vigor Side they decided to connect the Cisco with the Vigor, thoughout a Switch and as this want enough, the decided to put the 192.168.1.0 as WAN interface on VIGOR that hits a Provider Modem with Default Gateway or 1.254 (which is the same network in cisco Fa0/0)

Funny thing, they told....they want these 2 network to communicate with each other...hahaha...As cisco has internal lan 192.168.1.0 and Vigor uses the same range in it WAN!!! LOL

I don't want to tell them to simple re plan their network I am trying to figure out a Gyro Solution, where simple create a Sub interface on Fa0/0.100 as a 10.0.0.1 and to Vigor Lan2 10.0.0.2 and somehow put a static route on Vigor that 192.168.1.0 is out of 10.0.0.1. But it won't take it as 192.168.1.0/24 is used by Vigor in WAN1 !!!!!!

But here is what I am thinking. Could I create a loopback on Cisco, 1.1.1.1 and static ip route to vigor 1.1.1.1 from 10.0.0.1 (which it works and pingable) but how can I re route the traffic from the Loopback to 192.168.1.0 (internal Lan of Cisco)???

168.1.0Lan 192.168.9.0(lan Vigor) 192.168.1.0 (Wan1 Vigor)

Cisco ----- Switch ----- Vigor

Georg Pauwen · ‎03-26-2018

Hello,

how are the two sites connected, by VPN ? What is the WAN IP address of the Cisco side ?

Fotiosmark · ‎03-27-2018

This is the most Weid network Topology i have ever seen so far!

So let me try and explain!

***********************************************************

Cisco : Comapny 1

Switch: Company 1 Computers 192.168.1.0/24

Vigor: Company 2

Cisco Interface 1 inside LAN: 192.168.1.0/24

Vigor To Oxygen Modem: 192.168.1.100 - Oxygen MOdem: 192.168.1.254

Vigor Inside Lan Computers: 192.168.9.0/24

Cisco-------Switch---------Vigor------Oxygen Modem

********************************************************************************

So because I do not wish to change all of their network and their IPs when I am trying to do is to advertise Cisco network 192.168.1.0 to vigor and 192.168.9.0 From Vigor to Cisco Network.

So I created a sub interface on cisco 10.0.0.1 and an interface on Vigor 10.0.0.2

I have put a static route on Cisco of 192.168.9.0 out of 10.0.0.2.

On Vigor though I cannot Add a static route of 192.168.1.0 out of 10.0.0.1 because it already has a directly connected route to Wan for Oxygen Modem!!! :(

So I thought, why not create a Loopback interface on Cisco and put that as a static route on Vigor?

So yes, a loopback interface with a different Private IP is able to communicate with Company 2 network and the other way around!

What I am thinking is what if I can somehow make the 192.168.1.0 from Cisco, PBR route map through out the Loopback interface? So 192.168.9.0 can reach the Loopback and the loopback can re-route the traffic to 192.168.1.0

Cisco is connected through the internet through another Wan Line, plus a Dialer as a backup.

They don't want to use VPN between companies because they say that since it is Directly connected 1 network with the other, we could advertise the networks through static routes! But they will need to change the Oxygen Modem IP and therefore the Default Gateway! Meaning, Downtime.

So what do you think? :) Confused yet?

Georg Pauwen · ‎03-27-2018

Hello,

what device is the layer 3 routing currently configured on at Company 1 ? You say there is a switch: which IP address if the default gateway for the client computers, and where is it configured ?

Company 1: LAN 192.168.1.0/24 --> ? --> Company 2

Fotiosmark · ‎03-27-2018

Company 1 has the Cisco which is Connected to a Switch, which all their computers are connected, which then they connected an interface of that Switch, to the Company 2 Vigor.
Default gateway for the clients is from what I see from configuration, 192.168.1.1 (for Company 1)
On company 2 some PCs are going out from the Oxygen 192.168.1.100 and some others from different Wan links (they enabled Load Balancing)

Again, it is confusing...

Connections
C1 C1 C2
Cisco-----Switch-------Vigor

Georg Pauwen · ‎03-27-2018

Hello,

"So I created a sub interface on cisco 10.0.0.1 and an interface on Vigor 10.0.0.2"

On which device did you configure 10.0.0.1...on the switch at Company 1 ?

Is 192.168.1.1 an interface on that same switch at Company 1 ?

Fotiosmark · ‎03-27-2018

At Cisco router Cisco 1841
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 192.168.1.1 YES NVRAM up up
FastEthernet0/0.100 10.0.0.2 YES manual up up

And on Vigor Lan2 10.0.0.1

The switch is a 0 capabilities switch which their local IT set to interconnect stuff :@
K#ping 10.0.0.1 (To Vigor)

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.0.0.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

From Vigor
Pinging 10.0.0.1 with 64 bytes of Data through LAN
Receive reply from 10.0.0.1, time<1ms
Receive reply from 10.0.0.1, time<1ms
Receive reply from 10.0.0.1, time<1ms
Receive reply from 10.0.0.1, time<1ms
Receive reply from 10.0.0.1, time<1ms
Packets: Sent = 5, Received = 5, Lost = 0 (0% loss)

Fotiosmark · ‎03-27-2018

Routing Table from VIGOR
Key: C - connected, S - static, R - RIP, * - default, ~ - private
* 0.0.0.0/ 0.0.0.0 via 192.168.1.254 WAN1
C~ 192.9.200.0/ 255.255.255.0 directly connected LAN1
S public/ 255.255.255.255 via public WAN3
C~ 10.0.0.0/ 255.255.255.252 directly connected LAN2
S~ 10.11.0.0/ 255.255.255.0 via 10.0.0.2 LAN2
* 80.106.108.94/ 255.255.255.255 via 80.106.108.94 WAN3
* 80.106.108.219/ 255.255.255.255 via 80.106.108.219 WAN2
S 85.72.35.196/ 255.255.255.255 via 85.72.35.196 WAN2
C~ 192.168.9.0/ 255.255.255.0 directly connected DMZ
S~ 192.168.0.0/ 255.255.255.0 via 213.249.18.238 VPN-1
C 192.168.1.0/ 255.255.255.0 directly connected WAN1

Routing table from Cisco
Gateway of last resort is Public to network 0.0.0.0

Public/30 is subnetted, 1 subnets
C Public is directly connected, FastEthernet0/1.1
S 192.9.200.0/24 [1/0] via 10.0.0.1
Public/32 is subnetted, 1 subnets
C Public is directly connected, Dialer0
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.11.0.0/24 is directly connected, Loopback0
C 10.0.0.0/30 is directly connected, FastEthernet0/0.100
C 192.168.1.0/24 is directly connected, FastEthernet0/0
62.0.0.0/32 is subnetted, 1 subnets
C Public is directly connected, Dialer0
S* 0.0.0.0/0 [1/0] via Public