FRUSTRATION! DOES A SWITCH HAVE AN IP?

Lex · 22 Aug 2006 at 14:46

i would like to know does a switch have an IP address? My administrator seems to think that when we connect the switch it boots the mailserver off.

But i dont think thats the problem. Fair enough if the switch was a router but please someone tell me.

its a question that is driving me insane!

Stellios · 22 Aug 2006 at 14:47

As far as i know a switch doesnt have an IP as all it does is route traffic.

Lex · 22 Aug 2006 at 14:50

Stellios said:
As far as i know a switch doesnt have an IP as all it does is route traffic.

so i take it you cannot manage or configure a switch because you cannot connect to it? Or is that where a managed and unmanaged switch comes into play?

I thought every device on a network has an ip address?

Sone · 22 Aug 2006 at 14:54

managed switches have ip address's, some unmanaged ones have basic montoring interface which has an ip address(such as netgear). Some old hubs even have ip address's for monitoring(i have only seen on cisco)

edit, as you say every device has an ip, but think of hubs/switches as cables. Part of the physical network.

Lex · 22 Aug 2006 at 15:26

Sone said:
managed switches have ip address's, some unmanaged ones have basic montoring interface which has an ip address(such as netgear). Some old hubs even have ip address's for monitoring(i have only seen on cisco)

edit, as you say every device has an ip, but think of hubs/switches as cables. Part of the physical network.

so does that mean that a switch can knock another ip address off the network? You are telling me that switches have ip addresses...so i'm still confused.

If they do how can i find their ip address and give it a static ip address or assign the other workstations an appropriate dhcp range?

Deathwish · 22 Aug 2006 at 15:30

What switch do you have?

None of the switches I use here have an IP address.

Lex · 22 Aug 2006 at 15:35

Deathwish said:
What switch do you have?

None of the switches I use here have an IP address.

dynamode sw1600-r 16port switch

tonyyeb · 22 Aug 2006 at 15:40

Sone said:
managed switches have ip address's, some unmanaged ones have basic montoring interface which has an ip address(such as netgear). Some old hubs even have ip address's for monitoring(i have only seen on cisco)

edit, as you say every device has an ip, but think of hubs/switches as cables. Part of the physical network.

We have 5 port netgear switches which aren't managed which do NOT need an IP.

tonyyeb · 22 Aug 2006 at 15:41

Lex said:
dynamode sw1600-r 16port switch

Dynamode??? Why not get a cheap one instead!!! :rolleyes:

Lex · 22 Aug 2006 at 15:41

tonyyeb said:
We have 5 port netgear switches which aren't managed which do NOT need an IP.

right so they dont 'need' an IP does that mean they have a default IP? sorry to be a bugger but i want to know!

its so frustrating. does it then depend on the switch u buy ?

Deathwish · 22 Aug 2006 at 15:42

http://www.nirox.co.il/dynamode/www/details.asp?id=16

This one? Doesn't appear to have an IP address.

Lex · 22 Aug 2006 at 15:49

Deathwish said:
http://www.nirox.co.il/dynamode/www/details.asp?id=16

This one? Doesn't appear to have an IP address.

thats good enough for me buddy. I'm relativley convinced.

tonyyeb · 22 Aug 2006 at 15:50

Lex said:
right so they dont 'need' an IP does that mean they have a default IP? sorry to be a bugger but i want to know!

its so frustrating. does it then depend on the switch u buy ?

Our cisco switches which are managed and DO need an IP address will when first plugged in try to obtain an IP address from our DHCP server. We then connect to them and assign a STATIC ip so the we can manage them.

Why not shut down your mail server. Plug in the switch and then ping the IP address of the mail server. If it responds then something on the network (most likely the switch) has the same IP address of the mail server.

Some naff network hardware companies for ease of use set their devices up to use say 192.168.0.1 or 10.0.0.1 which would be a disaster for some places if you plugged that into your network!!! Our firewall is 192.168.0.1!!!

Lex · 22 Aug 2006 at 15:56

tonyyeb said:
Our cisco switches which are managed and DO need an IP address will when first plugged in try to obtain an IP address from our DHCP server. We then connect to them and assign a STATIC ip so the we can manage them.

Why not shut down your mail server. Plug in the switch and then ping the IP address of the mail server. If it responds then something on the network (most likely the switch) has the same IP address of the mail server.

Some naff network hardware companies for ease of use set their devices up to use say 192.168.0.1 or 10.0.0.1 which would be a disaster for some places if you plugged that into your network!!! Our firewall is 192.168.0.1!!!

what's special about 192.168.0.1 ? or 10.0.0.1 that ip is familiar to me i've seen it entered before.

tonyyeb · 22 Aug 2006 at 15:59

Lex said:
what's special about 192.168.0.1 ? or 10.0.0.1 that ip is familiar to me i've seen it entered before.

It is the first IP address in two of the most common private subnets. Anyone who uses Windows Internet Connection Sharing will have a subnet of 192.168.0.x by default.

Over Clocker · 22 Aug 2006 at 18:04

This is meant to be rude at all so please do not take it that way, but, if you/your administrator needs to ask these kind of questions, you really should not be touching the network infrastructure.

However, if the switch is knocking the mail server sideways when it is connected, and is not a managed switch with a static IP, it may well be shafted and a new one will suffice.

As has been suggested, disable the network on the mail server temporarily/unplug ints network cable, and then ping its IP and see if anything else responds.

Don't buy another Dynamode switch though

DJMK4 · 22 Aug 2006 at 18:15

Switches work on layer 2 meaning they work on MAC addressing rather than IP, Managed switches have IP i think..I.E layer 3 Switches..

Over Clocker · 22 Aug 2006 at 18:21

[Sniper][Wolf] said:
Switches work on layer 2 meaning they work on MAC addressing rather than IP, Managed switches have IP i think..I.E layer 3 Switches..

Nearly, but its more to do with how the switch communicates with devices on its ports - layer two "learns" the MAC address of each device on each port and communicates to its devices via MAC address.

Whether a switch has an IP or not depends on whether it has any user configurable options that require direct communication via, in most cases, a web interface. It's not just managed switches that have IPs, but nowadays many cheaper "smart" switches which are not really layer2/3 managed, but nonetheless have options that can be configured by communicating with its IP.

tonyyeb · 22 Aug 2006 at 18:36

[Sniper][Wolf] said:
Switches work on layer 2 meaning they work on MAC addressing rather than IP, Managed switches have IP i think..I.E layer 3 Switches..

Wikipedia has it

Layer 3 Switching

The major difference between the packet switching operation of a router and that of a Layer 3 switch is the physical implementation. In general-purpose routers, packet switching takes place using a microprocessor, whereas a Layer 3 switch performs this using application specific integrated circuit (ASIC) hardware.

lokkers · 22 Aug 2006 at 18:54

Over Clocker said:
suggested, disable the network on the mail server temporarily/unplug ints network cable, and then ping its IP and see if anything else responds.

As above, or if you dont want to take the mailserver offline, unplug a pc from the network, and plug that machine straight into the switch. ping the IP of the mailserver and see if you get a response.

Surely doesnt take a genius to work out :confused: