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dhcp 2
- Thread starter mikemes
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JasonC
MIS
How do you want to set it up? Are you looking to forward address's from a specified DHCP server to another network or are you looking to actually configure a DHCP Server?<br><br>JasonC
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Hope you dont mind me helping you clarify the question, Jason.<br><br>What we need to know is, Are you looking to get the DHCP<br>broadcasts forwarded from one segment (network) to another,<br>so they can reach a DHCP server (hopefully this is it) 'OR'<br>are you saying you want the router to be a DHCP server<br>itself?<br><br>Trying to make the router a DHCP server would be a almost<br>strange thing to do, when you have alternatives like running<br>it on a server platform like NetWare, NT4 server, or Linux.<br><br>Remember, anyones router performs best when it only has to<br>do one thing, route.<br><br>Leroy MCNE, MCSE, CCNA, CCDA
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Running DHCP on a router a strange thing to do? I'm curious as to why you say this? I don't want to start an argument, but I'm interested in your point of view and why you feel this way. So please don't take this the wrong way as I'd prefer a debate over this instead of a flame ware.<br><br>I have DHCP running on two seperate routers and am in the process of setting it up on another. In my network it works great. To me, this elminates one more thing in the network that could go wrong. It makes perfect sense to me to run this on the router, as it helps reduce costs. You don't need to purchase a seperate server, actually two if you want redundancy. You don't need to purchase additional software, unless you are using Linux or FreeBSD (personal favorite) and have good reliable open-source DHCP server software. You also don't need to purchase some type of tape backup and tapes to backup those servers. Since I already back up my router configs - doesn't everyone? - I know I've always got a backup. Yes, what you say is correct, a router will work best if it does only one thing, but in todays IT world, that's kind of unrealistic. Otherwise, cisco's IOS would not be so feature packed. If you're router is doing a dozen other CPU intensive tasks, I would advise not to put DHCP on it, but otherwise, use it. If you're using IPSec or some other tasks that are eating your CPU's utilization, then DHCP on the router isn't the way to go. But if you're router is sitting at 5% utilization, do it. You paid a good deal of money for that cisco router, put it to work for you! So I don't feel it is a strange thing to do. If you're router is already working pretty hard and taking on a good size load, don't burden it down further with DHCP, but instead, use a server platform for DHCP. But, if your router isn't doing a whole lot and it's utilization is very low, put DHCP on it, it's easy to configure and maintain. All this though is dependent upon what model router you have and what other functions it is currently doing.
ip dhcp database <A HREF="ftp://username
assword@10.10.10.10/router-dhcp" TARGET="_new">ftp://usernameassword@10.10.10.10/router-dhcp</A><br>ip dhcp excluded-address 172.20.0.0 172.20.9.255<br>ip dhcp ping packets 1<br>!<br>ip dhcp pool FOO<br> network 172.20.0.0 255.255.0.0<br> domain-name organization.com<br> default-router 172.20.0.1 <br> dns-server 172.20.0.2 172.20.0.3<br> lease 0 4<br><br>The ip dhcp database is optional, it's only if you want to keep some sort of database of the MAC addresses and what IP address they were assigned. The excluded-address keeps those addresses from being assigned to anyone. You can use those on your network for servers or any workstation that requires a static address. All you do is create a DHCP pool and name it, in the above example, it's named FOO. You specifiy the network you want to be used, again, this one is using the 172.20.0.0 class B segment. Remember though that only addresses starting with 172.20.10.0 - 172.255.255.254 will be handed out since we've excluded 172.20.0.0 - 172.20.9.255. You'll need to specify the domain-name your organization uses also. You setup what the default gateway for those machines will be, in this case, 172.20.0.1 and what DNS server they will use. In my example, I have two listed, a primary 172.20.0.2 and a secondary 172.20.0.3. Since these addresses are excluded from the DHCP pool, I can assign them to servers, the routers ethernet interface or any device that needs a static IP address. The lease on any IP address pulled from this pool will last only 4 hours. It's specified in days and hours. You can have the lease expire in 7 days and 12 hours if you wanted, though that's not advised, by using "lease 7 12".<br><br>This is a basic configuration and more than enough to actually get it up and running on your router. If your organization uses WINS along with, or instead of DNS, that can be accomplished using "netbios-name-server 172.20.0.2". There are other options that be set to tailor this to your organizations needs. Create a basic pool and then play around with it.<br><br>Hope this helps.
assword@10.10.10.10/router-dhcp" TARGET="_new">ftp://usernameassword@10.10.10.10/router-dhcp</A><br>ip dhcp excluded-address 172.20.0.0 172.20.9.255<br>ip dhcp ping packets 1<br>!<br>ip dhcp pool FOO<br> network 172.20.0.0 255.255.0.0<br> domain-name organization.com<br> default-router 172.20.0.1 <br> dns-server 172.20.0.2 172.20.0.3<br> lease 0 4<br><br>The ip dhcp database is optional, it's only if you want to keep some sort of database of the MAC addresses and what IP address they were assigned. The excluded-address keeps those addresses from being assigned to anyone. You can use those on your network for servers or any workstation that requires a static address. All you do is create a DHCP pool and name it, in the above example, it's named FOO. You specifiy the network you want to be used, again, this one is using the 172.20.0.0 class B segment. Remember though that only addresses starting with 172.20.10.0 - 172.255.255.254 will be handed out since we've excluded 172.20.0.0 - 172.20.9.255. You'll need to specify the domain-name your organization uses also. You setup what the default gateway for those machines will be, in this case, 172.20.0.1 and what DNS server they will use. In my example, I have two listed, a primary 172.20.0.2 and a secondary 172.20.0.3. Since these addresses are excluded from the DHCP pool, I can assign them to servers, the routers ethernet interface or any device that needs a static IP address. The lease on any IP address pulled from this pool will last only 4 hours. It's specified in days and hours. You can have the lease expire in 7 days and 12 hours if you wanted, though that's not advised, by using "lease 7 12".<br><br>This is a basic configuration and more than enough to actually get it up and running on your router. If your organization uses WINS along with, or instead of DNS, that can be accomplished using "netbios-name-server 172.20.0.2". There are other options that be set to tailor this to your organizations needs. Create a basic pool and then play around with it.<br><br>Hope this helps.
JasonC
MIS
And in case you wanted to forward the IP address's to another network segment config the router with a helper address.<br><br>interface Ethernet0<br> ip address 10.x.x.x 255.0.0.0<br> ip helper-address 10.x.x.x<br> bandwidth 10000<br> ipx network xxxx<br> no ipx route-cache<br> priority-group 1<br><br>You can configure this by doing the following:<br>conf t<br>int e0<br>ip helper-address x.x.x.x<br>CTRL Z<br>and copy run start<br><br>your all set if you already have a DHCP server<br><br>JasonC<br> <p> <br><a href=mailto:jcusick@visto.com>jcusick@visto.com</a><br><a href= > </a><br>
I don't know if any of the guys who discussed this are still using the Forum but I have a question.
Is the domain-name config statement relevant to NT or just when configuring for Website Access ???
Excuse me for dragging up an old thread but I've been using this config as a template to follow since April and am just about to put it into live operation. The Config I've got works without it in testing , but should I have it in there for some (not obvious) reason ???? Paul C.
s-)
Is the domain-name config statement relevant to NT or just when configuring for Website Access ???
Excuse me for dragging up an old thread but I've been using this config as a template to follow since April and am just about to put it into live operation. The Config I've got works without it in testing , but should I have it in there for some (not obvious) reason ???? Paul C.
s-)
either the domain-name just adds the someone.com qualifier to any name that did not have the fully qualified domain name to start with.
Here is a clip from Cisco's docs about it:
::Snip::
The global configuration command ip domain-name defines a default domain name the terminal server uses to complete unqualified host names (names without a dotted domain name appended to them). The syntax of this command follows:
ip domain-name name
no ip domain-name
The argument name is the domain name; do not include the initial period that separates an unqualified name from the domain name.
The no ip domain-name command disables use of the Domain Name System.
Example:
This command
!
ip domain-name cisco.com
!
defines cisco.com to be used as the default name. Any IP host name that does not contain a domain name, that is, any name without a dot (.), will have the dot and cisco.com appended to it before being added to the domain name system.
By default, IP Domain Name System-based host-name-to-address translation is enabled. To enable or disable this feature, use the ip domain-lookup global configuration command as follows:
ip domain-lookup
no ip domain-lookup
The no variation of the command disables the feature; the ip domain-lookup command restores the default.
:::snip::::
Mike S
the domain-name just adds the someone.com qualifier to any name that did not have the fully qualified domain name to start with.Here is a clip from Cisco's docs about it:
::Snip::
The global configuration command ip domain-name defines a default domain name the terminal server uses to complete unqualified host names (names without a dotted domain name appended to them). The syntax of this command follows:
ip domain-name name
no ip domain-name
The argument name is the domain name; do not include the initial period that separates an unqualified name from the domain name.
The no ip domain-name command disables use of the Domain Name System.
Example:
This command
!
ip domain-name cisco.com
!
defines cisco.com to be used as the default name. Any IP host name that does not contain a domain name, that is, any name without a dot (.), will have the dot and cisco.com appended to it before being added to the domain name system.
By default, IP Domain Name System-based host-name-to-address translation is enabled. To enable or disable this feature, use the ip domain-lookup global configuration command as follows:
ip domain-lookup
no ip domain-lookup
The no variation of the command disables the feature; the ip domain-lookup command restores the default.
:::snip::::
Mike S
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