Cisco Vlan and IP helper

Your description of the problem raises several questions and one comment.

Comment: You've "implemented VLAN's" --- If you were using switches (as opposed to hubs) you were already using VLAN's - probably VLAN 1.

Question 1: You are using VLAN 20 and the helper addresses you gave seems to indicate the subnet 10.1.20.0/24. Is VLAN 20 the same VLAN as where the 10.1.20.x addresses are? If this is true, then you don't need the ip helper addresses at all due to the fact that the broadcasts are already reaching their intended target.

Question 2: Assuming the answer to question 1 is that 10.1.20.x is NOT on VLAN

20... Why are you including the IP address of the Citrix server in the forwarding of the UDP broadcasts? - Does the Citrix machine serve as a DHCP server as well?

Question 3: What purpose does forwarding UDP port 1609 serve to help in the problem you are experiencing?

JC

Sorry, I should have been more clear. I was typing on a laptop in a telco closet and tried to keep it short.

Our 10.1.20.x network was not switched, and what was switched was VLAN

1 We've moved everything to switches, so the 20 network is still on vlan

1. Each of our closets is now one a 172.16.x.x network. Example, Ground Closet is 172.16.12.x.

10.1.20.x needs to be kept from some legacy vendor controlled servers (it would be a PAIN in the butt to re-ip them).

The reason I did an IP helper and a udp port forward for port 1609 on the vlan 12 interface (172.16.12.x), is because the citrix clients can't "DISCOVER" the citrix server. I'm assuming citrix uses some kind of broadcast to discover the server farm. I searched some news archives and saw reference to port 1609 UDP. If I manually enter the server farm address in the client, everything is well.

My goal is to get the autodiscover feature of the citrix client working again.

Thanks for your input!

Bill

try

ip forward-protocol udp 1604

Alosmake sure you disable each of the UDP broadcast that is automatically enabled whne ip helper-address is configured on an interface.

Asuuming you have WINS server for NETBIOS, then

! Define protocol forwarding on the firewall. When you turn on a related command, ! ip helper-address, you forward every IP broadcast in the ip forward protocol ! command list, including several which are on by default: TFTP (port

69), ! DNS (port 53), Time service (port 37), NetBIOS Name Server (port 137), ! NetBIOS Datagram Server (port 138), BOOTP client and server datagrams ! (ports 67 and 68), and TACACS service (port 49). One common ! application that requires helper addresses is Dynamic Host Configuration ! Protocol (DHCP). DHCP protocol information is carried inside of BOOTP packets. The ! "no ip forward protocol" statements turn off forwarding for the specified protocols.

no ip forward-protocol udp netbios-ns no ip forward-protocol udp netbios-dgm no ip forward-protocol udp domain no ip forward-protocol udp time no ip forward-protocol udp tacacs no ip forward-protocol udp tftp

ip forward-protocol udp bootpc ip forward-protocol udp bootps