I came apon a job whose network layout is kind of tricky. Here is the skinny:
2 routers (both 1721s). One is SBCs and it plugs into the internet on WIC interface. Nic interface plugs into a PIX 506E Firewall. The firewall does the PAT. The other eth port on the firewall plugs into the switch. The other router's WIC card plugs into the franchise intranet, and the NIC plugs into the switch.
All the PCs, servers, etc have the default gateway set to the ethernet interface of the franchise 1721. That router looks at the destination address and decides if it needs to go out it's WIC (if the dest. address is on the corporate intranet's subnet) or if it needs to go out to the internet (through the firewall and out the other router).
Now heres what I am trying to accomplish:
The customer wants to be able to telnet into one machine in the private network from her house.
Obviously, I need an ACL on the SBC router because thats where the request is comming from. I also have set up static NAT on the router from a public IP (in our valid range that SBC provides) and the private IP of the machine that she wants to access.
Currently, it is not working. I thought it had something to do with the other router so I started contacting the network engineers at the franchise office to get them to open up their router to allow telnet.
I now think however, that the reason it is not working is I have the static NAT on the wrong device!!
Shouldn't it be on the firewall, because the SBC router doesn't know anything about those private addresses (the PAT happens on the firewall).
Is my hunch right? Can you please advise me on what devices will needs changes in their ACLs and which device(s) will need static NAT mapping? I don't want to open any thing I don't have to. Thanks!!
from your description it indeed looks like your firewall needs the NAT. The SBC router has only public IP addresses, right ? That means your external host coming from the Internet will need to be allowed on the SBC router and the firewall, so you need to change any access lists on those devices to allow the external host. Then, if the franchise router has access lists as well, you need to allow the translated private space address inbound as well.
Let me know if you run into more trouble with this...
I'm going back to that client this afternoon so I will try this out.
Are you sure the franchise router needs to be opened up? I thought only the SBC router will see the inbound traffic because when the external host hits the SBC router, than makes it through the firewall, they are at the switch and the same subnet that the internal machine is on.
I was thinking that franchise router doesn't matter because default gateways are only used for outbound traffic. Would the franchise router need an ACL for outbound traffic? Which address (private or public)?
sorry for the misunderstanding: the franchise router indeed does not need an ACL, I just meant to say that if you have one already configured, make sure it allows the traffic in from the PIX for the respective private space address that the PIX has NATted...
I just came from the clients office. I am a little lost here. I am quite nifty at the CLI of a router or a switch, but every other firewall I have dealt with (Sonicwall, Watchgaurd, etc) has had a web based GUI. I am new in the field and have never configured a PIX before.
Here's what I have right now:
SBC router is configured to allow Telnet traffic in.
The PIX 506E has PAT configured on it. I tried setting up static NAT with no luck on the firewall. Attached is my running config. Perhaps you could instruct me on a some commands I can throw at this box to make this whole mess work!!
Let 22.214.171.124 be the address of the internal machine we want to access and SERVER.PUBLIC.IP be the public address we should point our telnet client to get in.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.