Can't set up manual IP address

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Level 4

1,836 points

Can't set up manual IP address

I want my Mac to have a fixed IP address for a number of reasons. Up to now I've been using the automatic DHCP which gives a new IP address each time.

I've gone into the network system preferences and to built in ethernet and changed the setting from "Using DHCP" to "Using DHCP with manual address"
put in the same IP address and click apply

I was immediately disconnected from the internet. I went back to Using DHCP and click apply and I'm connected again, still with the same IP. So I tried fully Manual and put in same IP but also the same Subnet Mask and Router.

Again I am immediately disconnected from the internet. Go back to auto DHCP and I'm connected again immediately even though all settings are the same.

What's going on? I've tried this on 2 different days with two different IP addresses and the same thing happens.

I even changed the IP address and got the same result.

Kevin

Quicksilver dual 1.5 gig, Mac OS X (10.4.7)

Posted on Oct 6, 2006 2:11 PM

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Answer 1

Camelot

Level 9

59,493 points

Oct 6, 2006 3:44 PM in response to Kevin Horn

On one of the other Macs that is working, open /Applications/Utilities/Terminal.app and run the following commands:

ifconfig -a

and:

netstat -rn

This will give enough information about the configuration of a working machine to be able to determine what values you should set manually on your machine.

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Answer 2

Camelot

Level 9

59,493 points

Oct 6, 2006 2:27 PM in response to Kevin Horn

What's your DHCP server?

It's quite possible that it's not supporting DHCP with manual - in that you can't manually use an IP address in the DHCP range. The server wants to hand out the address in order to support it.

You might be able to get it to work by choosing an IP address in the same subnet, but outside of the DHCP range, but you'd need to look at your DHCP server configuration to be able to determine what an appropriate address would be.

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Answer 3

Kevin Horn Author

Level 4

1,836 points

Oct 6, 2006 2:59 PM in response to Camelot

What's your DHCP server?

Have no idea, how would I find out?

It's quite possible that it's not supporting DHCP
with manual - in that you can't manually use an IP
address in the DHCP range. The server wants to hand
out the address in order to support it.

I'm able to set up a fixed IP address on my PC.

You might be able to get it to work by choosing an IP
address in the same subnet, but outside of the DHCP
range, but you'd need to look at your DHCP server
configuration to be able to determine what an
appropriate address would be.

I'm sure it's in the right range, current IP is 10.0.0.166. I've seen everything from 100 on the last number to 170. I'm in a small office with about 10 PC's and 2 Macs. I don't even know where the incoming router is or what kind it is and no one here knows, nor can I ask the boss to spend the money to bring a network guy in. Nor can I mess with everyone's network.

I do have a fixed address on my PC which acts as a print server for me. But when everyone comes in in the morning and turns on their computers there's a new set of IP addresses all around. If I turned my PC off there's a chance when I turn it back on my fixed IP will have been taken and I have to assign a new one and reset Print Utility with the new IP printer. This happens every 2-3 weeks.

But I want the other Mac in the office to be able to drop files on my Mac but neither of us show up on the network and asking him to redo the IP address to connect to me everyday will get old pretty fast (he doesn't even know what an IP address is).

Kevin

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Answer 4

Kevin Horn Author

Level 4

1,836 points

Oct 6, 2006 3:51 PM in response to Camelot

OK, I ran them now what does all this mean:

lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1
inet 127.0.0.1 netmask 0xff000000
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0 mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
inet6 fe80::203:93ff:fe86:ad80%en0 prefixlen 64 scopeid 0x4
inet 10.0.0.173 netmask 0xffffff00 broadcast 10.0.0.255
ether 00:03:93:86:ad:80
media: autoselect (100baseTX <full-duplex>) status: active
supported media: none autoselect 10baseT/UTP <half-duplex> 10baseT/UTP <full-duplex> 10baseT/UTP <full-duplex,hw-loopback> 100baseTX <half-duplex> 100baseTX <full-duplex> 100baseTX <full-duplex,hw-loopback> 1000baseT <full-duplex> 1000baseT <full-duplex,hw-loopback> 1000baseT <full-duplex,flow-control> 1000baseT <full-duplex,flow-control,hw-loopback>
fw0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 2030
lladdr 00:03:93:ff:fe:86:ad:80
media: autoselect <full-duplex> status: inactive
supported media: autoselect <full-duplex>

Routing tables

Internet:
Destination Gateway Flags Refs Use Netif Expire
default 10.0.0.100 UGSc 33 15 en0
10/24 link#4 UCS 6 0 en0
10.0.0.100 0:a0:c8:b:6f:0 UHLW 32 6 en0 30
10.0.0.125 0:f:1f:4a:90:6e UHLW 0 1354 en0 1025
10.0.0.173 127.0.0.1 UHS 0 38 lo0
10.0.0.176 0:a0:cc:a2:65:1c UHLW 0 0 en0 1026
10.0.0.178 0:40:2b:68:4c:24 UHLW 0 0 en0
10.0.0.241 0:a:95:e8:fd:62 UHLW 0 8 en0 1195
10.0.0.255 ff:ff:ff:ff:ff:ff UHLWb 0 6 en0
127 127.0.0.1 UCS 0 0 lo0
127.0.0.1 127.0.0.1 UH 16 16013 lo0
169.254 link#4 UCS 0 0 en0

Internet6:
Destination Gateway Flags Netif Expire
::1 ::1 UH lo0
fe80::%lo0/64 fe80::1%lo0 Uc lo0
fe80::1%lo0 link#1 UHL lo0
fe80::%en0/64 link#4 UC en0
fe80::203:93ff:fe86:ad80%en0 0:3:93:86:ad:80 UHL lo0
ff01::/32 ::1 U lo0
ff02::/32 ::1 UC lo0
ff02::/32 link#4 UC en0

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Answer 5

Camelot

Level 9

59,493 points

Oct 7, 2006 1:21 AM in response to Kevin Horn

OK, the pertinent parts of that output are:

inet 10.0.0.173 netmask 0xffffff00 broadcast 10.0.0.255
...
default 10.0.0.100 UGSc 33 15 en0

That's telling me that your network uses 10.0.0.0/24 (effectively giving you a usable range from 10.0.0.1 through 10.0.0.254).
Additionally, your router is at 10.0.0.100.

So, in theory you should be able to choose any address in the 10.0.0.1 through 10.0.0.254 range as long as it's not already in use. From your earlier post you should probably avoid anything that the DHCP server hands out (which sounds like anything above 10.0.0.100), so pick something lower.
To be safe you should ping it from a functioning machine first to make sure the number you pick isn't already in use by another machine.

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Answer 6

Kevin Horn Author

Level 4

1,836 points

Oct 7, 2006 11:15 AM in response to Camelot

Just tried that and it doesn't work. I tried all the highest and lowest numbers and nothing will connect until I switch back to auto DCHP.

Kevin

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Answer 7

Oct 9, 2006 9:27 PM in response to Kevin Horn

I have the same response from my LAN setup ... 3 Macs and a PC.

Won't allow manual setup, and requires DCHP under Automatic mode.

I believe it has to do with the router's settings. Mine is an Asanté FR3004FLC which has a setting for a local DHCP Server, with range of values for the Local IP Addresses to assign. I have it Enabled.

This is required by other settings of my router, and possibly by the ISP requiring use of PPPoE ... so only automatic mode on the Mac makes the connection to the internet.

Still haven't figured exactly what it is ... but I have not used the Static IP Address capability of the router ... just the DHCP Server configuration.

It seems so complicated ... options nested within options ... that I have all but given up after getting a config to work ... spent 4 days doing just that ...

Let me know what else is discovered on this topic.

Mac Plus, Performa 6116, PPC 8500 G4/450, 9500 G3/500, QS 2@1GHz Mac OS X (10.3.9)

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