Two gateways

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Hello fellow technibblers,
I am stumped on a networking issue that is said to have started when a Cisco catalyst 2960 and two virtual dns were installed (replaced some older equipment) at a local police department.

Before I get into the issue let me explain the network. There's about 15-20 pcs and two servers with a couple of virtuals on each (vSphere) there's two Fortigate 60Ds running in HA mode connected to the cisco switch and from there all machines are hard wired. Most machines are running Windows 7 Pro with some running 8 and 10, two of the "decommissioned" pcs in the dispatch area are running... dare I say, Windows 2000.

Also connected to the Cisco switch is a gateway that connects to the county prosecutors office. This gateway has the local ip of 10.10.10.200/24 and only allows 4 local IPs through .17, .18, and I forget the two others. Those (static) IPs belong to the detectives computers. (17 and 18) the other two belong to the two windows 2000 computers. Internet access is prohibited through the .200 gateway. So the Fortigate remain as the default gateways and a local HOST file directs the traffic to the county's (.200) gateway. This works... Sometimes! It's intermittent with it, however, same host file, works 100% of the time on the old dispatch computers that run win 2000.

A couple of things to note:
- the Cisco switch is pretty much a dummy, no VLans or anything, just a static ip, all ports turned on
- I thought I solved the issue about a month ago because when I ran an ip scan, the .200 address was leased to a different device. (DHCP pool was including .200 without a reservation) so I removed it from the pool completely, but the issue came back less than a week later. Most computers are static, the DHCP range is now .205-.240 and an IP scan shows everything is the device it should be and I don't see any extraneous devices that could be giving our ips.
-DHCP on the two fortigates are turned off.
-during the outage I can ping .200 gateway most of the time. With the rare occasion where it's Unreachable.
- there aren't any other network issues, Internet works fine, printing ...etc
-checked the ACLs on the fortigates and there is nothing that should be preventing it.
-lastly I the .200 gateway is not the local pds gateway and therefore I'm not authorized to touch it/check the config, but they have been very good in responding to requests to check things.

I am honestly stumped. I'm at the point where I want to request to nix the gateway from the switch to county and have a direct connection to the fortigates. And take my own control for NAT and ACL from the detectives computers to the county.

I would really like to run a packet sniffer and see where the packets are getting dropped... I haven't used one in about a year or two so I'm rusty to say the least... Any tips on sniffing properly?

Tomorrow I'm going to try to examine the OS side of things, sfc/scannow and maybe a reimage.

Help nibblers! Pleaseeeeeeeee




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Instead of using the hosts file couldn't you create a static route on the Fortigate for whatever the remote network is using going via 10.10.10.200?
 
Interesting approach.
What I'd do, on those rigs with a static that are not allowed to the red side, I'd manually assign the static IPs, but I'd leave the gateway out.
Example...
IP 10.10.10.17
SNM 255.255.255.0
gateway (leave empty/blank)
DNS..whatever the DCs IP is.

Having DHCP hand out the reservations for those Win2K rigs....including the normal gateway for the rest of the network (assuming .1)...and then trying to over-ride it with the old HOST file...to me just screams a bit of a conflict.
 
I am a bit confused that you mention the hosts file is used to redirect traffic. That would usually be a static route on the workstation or route on the Fortigate firewall. I would certainly type 'Route print' on all workstations and see if I can see the permanent static routes. If you are getting intermittent replies when pinging across a routed network (including over the internet) then a fantastic free to to see where your packets are getting dropped is WinMTR. run winmtr for a bit. http://winmtr.net/download-winmtr/
 
If the change of Cisco has introduced an issue then whoever changed that should be invited to investigate by comparing the configurations. I would certainly check the MTU on the new Cisco switch and would use the documented ping test to see what the largest package that could be transmitted without fragmentation is.
 
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Yeah, true.."route" command...not hosts file. Been so long since I've used the poor mans WINS....I spaced out agreeing about the host file.
Oops didn't see your reference at the end, I was just replying the the original post! And poor man's WINS would be the LMHOSTS file LOL. HOSTS is the upgraded version, poor man's DNS!!

Also OP, I am not sure what you mean by virtual DNS. If the DNS servers have changed then could your intermittent connectivity be a name resolution problem rather than IP routing problem? The hosts file entry might work around that.
 
Yes! The workstation is doing routes. The host file is just doing the translations. (See attached) .250 is the fortigate. I can put the static routes into the Fortigate.

I'll remove the default gateway from the detective pcs. And the Windows 2000 computers are also static. Same host file and same routes. IMG_1111.JPG

I'm going to download that and try it tomorrow, I'll try and post the results!




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