Local DHCP or DHCP Relay to "main" LAN / DNS across WAN or DNS Cache?

[jfk8680]

Hi,

I have got two questions which kind of address the same area. My company has got some branch offices which all connect to the HQ using DSL lines. Each location uses a seperate subnet and they are connected using Cisco DSL Routers.

My goal is to remove all server hardware from the branch offices and equip all those users with thin clients which connect to a Citrix farm on the HQ. I have got a few design options which I would like to share:

1. Should I use a local DHCP server at each office or should I configure a DHCP relay agent on each subnet which forwards DHCP traffic to a DHCP server on the HQ LAN?

2. Should I use a DNS Cache only server at each branch office or should I let all DNS traffic cross the WAN connections to the DNS servers located at the HQ.

All sugestions are welcome!

regards,

Jeffrey

 

[GlenJohnson]

Depends, you don't mention how many locations and clients. A cache only server doesn't really replicate with other dns servers, so the traffic isn't as heavy. The only time the traffic picks up is if the cache is emptied because of a re-boot, or ipconfig /flushdns. It does cause problems if the users are going to sites that are new so it isn't in cache. How bout some more info? Thanks.

Glen A. Johnson
"Fall seven times, stand up eight."
Proverb

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[jfk8680]

Glen,

Thank you for your response. I tried to picture the situation as simple as possible but I guess you are right that some more info is needed. Here goes:

Actually there are several (about 10) "main" locations, which I called HQ in my first post, which all have several (5 to 10) "remote" locations (branch offices). Each main location has 30 to 80 users and each remote location has 10 to 30 users. These companies operate on their own but they are all part of a corporate financial company. All these offices are connected to a huge nation-wide DSL private network. In my first post I zoomed in on one main location and it's branch offices but in reallity there are about 10 of those networks.

Our goal is to standardize the network design for all these locations but one location can have as few as 5 users while others can have as much as 40 users.

I guess the main question is: does Citrix (the ICA protocol) generate such an amount of DHCP and DNS traffic that it justifies a local DHCP and DNS (cache only or maybe even a secondary DNS?) server at each branch office. I know the DHCP routines and know how DNS operates but I find it hard to estimate the amount of traffic which will cross the WAN if there are no local servers. I think it is also usefull to know that VoIP traffic (with QoS) will also be crossing the same WAN links...

I hope this is enough information for you!

thank you,

Jeffrey