IP ranges on switches, how do you do it?

[Kyle]

The school i am at now have around 25 switches on their network. They Ip address's of these are in the IP range that is assigned to the school. THe school have 1024 address assigned by the LEA. The people who put the switches in used 25 IP from the exluded range at the bottom of the range (10 to 35). They aslo added the address tothe DNS records manually???

 

The switches do have static IP's but we had a power cut the other week and 4 of them have lost their static IP and are now being assigned by DHCP. I have seen before where some school have their Switches set up like this but add the records to DHCP as reservations puerly for record keeping but still keep keep all the switches as static.

 

Now i am no network guru by any means so could someone advise me what it best practice here. Should they be added to DHCP or DNS just for record keeping? Or should be doind something else?

[DMcCoy]

dhcp is a bad idea for core networking devices. It's always good to have the network infrastructure accessible even if services like dhcp/dns are off.

 

I do the same here, static ips for the switches and then add them manually to dns so I can use a more memorable name to contact them, although often I use the ip for frequently used switches.

[BaccyNet]

All our switches are setup with static IP's at the far end of the range (excluded by DHCP) I dont add them to DNS (personally dont see the need) but do keep a record of their IP on a label on the switch as well as in a spreadsheet. Makes things easier when needing to change port VLANS:)

[tmcd35]

We have four IP ranges, 10.96.232.x, .233.x, .234.x, .235.x, The first range (232.x) is reserved for any thing that needs static IPs, the rest are allocated by DHCP. We do something like 232.0-50 are for servers, 232.51-100 are for switched, 232.101-150 are for admin pc's, 151-200 are for printers, 201-254 for WAP's.

 

Not entirely accurate but you get he idea.

[FN-GM]

We have four IP ranges, 10.96.232.x, .233.x, .234.x, .235.x, The first range (232.x) is reserved for any thing that needs static IPs, the rest are allocated by DHCP. We do something like 232.0-50 are for servers, 232.51-100 are for switched, 232.101-150 are for admin pc's, 151-200 are for printers, 201-254 for WAP's.

 

Not entirely accurate but you get he idea.

 

yer we do something similar to that.

[sippo]

We have four IP ranges, 10.96.232.x, .233.x, .234.x, .235.x, The first range (232.x) is reserved for any thing that needs static IPs, the rest are allocated by DHCP. We do something like 232.0-50 are for servers, 232.51-100 are for switched, 232.101-150 are for admin pc's, 151-200 are for printers, 201-254 for WAP's.

 

Not entirely accurate but you get he idea.

 

Great minds think a like! Its so much easier to manage when you have 'number structure'.

[plexer]

I'm just making sure all of mine are up to date as we changed some switches over the summer.

 

I use the first 15 or so excluded addresses from my range for servers, then I work down from .50 for my printers.

 

My switches are at the bottom of the second range and my waps at the top of it.

 

All recorded in excel.

 

Ben

[pete]

We keep network devices in another range on static ips and write it on the switch and in the wiki. Not sure whether it's a good or bad sign that I can remember the ips for most of them.

[Geoff]

Ideally, you want a separate VLAN and a separate IP space for your switches. That way you can isolate the management functionality (eg web https/ssh login).

[plexer]

Or you can restrict ip's that can login to them to acheive this if you can't do that.

 

Ben

[Geoff]

Except that there's nothing to stop someone changing their IP. If you want real management authentication on your switches, use TACAS+ Edited September 26, 2008 by Geoff

[Jay]

We have four IP ranges, 10.96.232.x, .233.x, .234.x, .235.x, The first range (232.x) is reserved for any thing that needs static IPs, the rest are allocated by DHCP. We do something like 232.0-50 are for servers, 232.51-100 are for switched, 232.101-150 are for admin pc's, 151-200 are for printers, 201-254 for WAP's.

 

Not entirely accurate but you get he idea.

 

You might want to exclude the bottom 7 addresses from DHCP on each 24 bit subnet since they will permit the workstations unfiltered FTP out. (Norfolk config). I'd allocate these via reservations to staff members who might find it useful.