Reply
Topic Options
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
Re: routing from dhcp server to switch
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-21
10:57 AM
2013-10-21
10:57 AM
routing from dhcp server to switch
Hi all,
If i were to create on my dhcp server different networks (vlans) how would i route it from the dhcp server to the different vlans on the switch( obviously i will have to create the different vlans on the switch) would i need a L2 switch or L3 switch or just a vlan managed switch?
Message 1 of 13
Labels:
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
03:44 AM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
04:00 AM
2013-10-22
04:00 AM
Re: routing from dhcp server to switch
ok now im really confused as i dont know what switch to get the L2 or L3 switch as i have found the page to configure the L3 switch for dhcp relays
http://kb.netgear.com/app/answers/detail/a_id/21989
can anyone help as im really confused
http://kb.netgear.com/app/answers/detail/a_id/21989
can anyone help as im really confused
Message 3 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
05:09 AM
2013-10-22
05:09 AM
Re: routing from dhcp server to switch
It may be a little more complex than you think AND Netgear has also blurred the lines between what they consider layer 2 & layer 3 switches making the decision even more challenging.
First - background - traditionally L2 switches do not route, L3 switches do - so, at least in theory - you need an L3 switch to do what you want - another option is to use an L2 switch and a router that supports VLANs.
Second - for what you are trying to do - you need to use something called DHCP relay - which is where a device known as an agent will relay the DHCP request from the VLAN where the address is required to the VLAN where the DHCP server resides - the DHCP agent can be on a PC with a static address, or, the L3 switch, or the router linking the VLANs - so whatever switch you choose you need to make sure it supports DHCP relay.
Third - your DHCP server also has to be able to work with a relay agent or you won't get the address you need, where you need it - not all DHCP servers can do this.
First - background - traditionally L2 switches do not route, L3 switches do - so, at least in theory - you need an L3 switch to do what you want - another option is to use an L2 switch and a router that supports VLANs.
Second - for what you are trying to do - you need to use something called DHCP relay - which is where a device known as an agent will relay the DHCP request from the VLAN where the address is required to the VLAN where the DHCP server resides - the DHCP agent can be on a PC with a static address, or, the L3 switch, or the router linking the VLANs - so whatever switch you choose you need to make sure it supports DHCP relay.
Third - your DHCP server also has to be able to work with a relay agent or you won't get the address you need, where you need it - not all DHCP servers can do this.
Message 4 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
11:57 AM
2013-10-22
11:57 AM
Re: routing from dhcp server to switch
Awesome thankyou for your reply, basically in using MS DHCP server and i have 4 network scopes, and im thinking of buying the M4100 D12G and it says it does dhcp relay so Il get the switch to dhcp relay to my dhcp server, or wont that work?
Message 5 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
12:03 PM
2013-10-22
12:03 PM
Re: routing from dhcp server to switch
Ive noticed you can have a dhcp relay on the dhcp server instead of on the switch, what's best practice
Message 6 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
06:38 PM
2013-10-22
06:38 PM
Re: routing from dhcp server to switch
robina_80 wrote: Awesome thankyou for your reply, basically in using MS DHCP server and i have 4 network scopes, and im thinking of buying the M4100 D12G and it says it does dhcp relay so Il get the switch to dhcp relay to my dhcp server, or wont that work?
Check the DHCP server - does it support option 82 - the versions I have used (upto 2008) don't - 2012 might.
Message 7 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
06:41 PM
2013-10-22
06:41 PM
Re: routing from dhcp server to switch
robina_80 wrote: Ive noticed you can have a dhcp relay on the dhcp server instead of on the switch, what's best practice
The DHCP relay needs to be on the LAN segment or VLAN with the clients that need the address in order to relay the DHCPDiscover broadcast to the DHCP server - if you're going to put a DHCP server on every segment (or VLAN), why use DHCP relay at all?
Message 8 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-22
11:39 PM
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-23
03:34 AM
2013-10-23
03:34 AM
Re: routing from dhcp server to switch
I was hoping you weren't going to ask that - open the DHCP server, pick a scope and look at scope options - the scope options are where you set the default gateway, DNS servers, time server, etc., - option 82 is "relay agent information".
Message 10 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-23
10:37 AM
2013-10-23
10:37 AM
Re: routing from dhcp server to switch
Looks like option 82 is on server 2012, Il get m4100 d12g switch and use just the dhcp relay function only,
What switch would you recommend btw to use, is the switch i said good?
What switch would you recommend btw to use, is the switch i said good?
Message 11 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-23
02:45 PM
2013-10-23
02:45 PM
Re: routing from dhcp server to switch
A long time ago my managing director called me in to his office and said to me "I strongly recommend, that you don't recommend".
I guess you are as puzzled by that recommendation as I was, all those years ago - the long & the short of it is, that if you're going to recommend something you should have valid reasons to do so - I've never used that switch, I have no idea of it's capabilities, it's strengths or it's weaknesses - therefore I should not recommend it - it might be perfect for your application - but I have no way of knowing that.
I guess you are as puzzled by that recommendation as I was, all those years ago - the long & the short of it is, that if you're going to recommend something you should have valid reasons to do so - I've never used that switch, I have no idea of it's capabilities, it's strengths or it's weaknesses - therefore I should not recommend it - it might be perfect for your application - but I have no way of knowing that.
Message 12 of 13
- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
2013-10-23
02:50 PM
2013-10-23
02:50 PM
Re: routing from dhcp server to switch
So what switch would you recommend then as I'm leaning towards an hp and I know I shouldn't as I'm on a netgear forum!!!
Message 13 of 13