First of all, i know that this is not the best place to ask this quesiton,
but it is the only place that can quickly come to mind...
I have a customer who has a block of 62 ip addresses (206.206.162.130 ->
206.206.162.190 and one for network/brodcast). They are current expanding
their network, and need around 30 more ip addresses. I went ahead and
allocated them the following IP address pool (207.66.81.144 ->
207.66.81.174 with network/brodcast address.) I attempted to use the new
address on a Apple Macintosh (PowerMac 6500/75) and it erturned an error
message saying that the router was not on the subnet, and that it could
not use the new address. I know I should remember how to fix that, but I
am not sure what to do.... Any help or guidence would be greatly
appreciated. Thank you very much.
I think, you can use virtual address (especially in Cisco, ip address ...
secondary) for
new network.
For example, router has 206.206.162.190 as local network's ethernet port.
If you want to use new address block at same network,
you can assign 207.66.81.174 to same port's secondary.
It's syntax is simple.
If your cisco router port is e0, you can use this serial command as reference.
ena
Password: <-- enter enable password
router# config
inter e0
ip address 207.66.81.174 255.255.255.224 secondary
exit
exit
router# wr
It is simple. If the customer's network has one backbone, this method can
handle their network as seperate two network. ;>
And every computer set their subnet's router IP address for their gateway
address.
Is it clear?
If you have problem with this, please e-mail me. ;>
HyunSeog Ryu
Kyle D. Smith wrote:
Are you trying to set up that IP address block as one subnet or two? That
IP block would be two valid /28s (207.206.81.144/28 and
207.206.81.160/28), but it isn't a valid /27.
hint: For a valid /27 (block of 32 IP addresses), the last octet of the
network address needs to be a multiple of 32.
-Steve
You made a subnetting error. You've gotta break it on a boundry. When
using /27 networks, it breaks up as follows:
Network Broadcast
a.b.c.0/27 .31
a.b.c.32/27 .63
a.b.c.64/27 .95
a.b.c.96/27 .127
a.b.c.128/27 .159
a.b.c.160/27 .191
a.b.c.192/27 .223
a.b.c.224/27 .255
Jeremiah
First of all, i know that this is not the best place to ask this quesiton,
but it is the only place that can quickly come to mind...
I have a customer who has a block of 62 ip addresses (206.206.162.130 ->
206.206.162.190 and one for network/brodcast). They are current expanding
their network, and need around 30 more ip addresses. I went ahead and
allocated them the following IP address pool (207.66.81.144 ->
207.66.81.174 with network/brodcast address.) I attempted to use the new
address on a Apple Macintosh (PowerMac 6500/75) and it erturned an error
message saying that the router was not on the subnet, and that it could
not use the new address. I know I should remember how to fix that, but I
am not sure what to do.... Any help or guidence would be greatly
appreciated. Thank you very much.
For a quick reference, download ftp://ftp.isi.edu/in-notes/rfc1878.txt
This will give you some templates for VLSM subnets. Here are some relevant
sections:
255.255.255.192 4 nets N.N.N.0 N.N.N.1-62 N.N.N.63
2 bit Class C 62 N.N.N.64 N.N.N.65-126 N.N.N.127
10 bit Class B N.N.N.128 N.N.N.129-190 N.N.N.191
N.N.N.192 N.N.N.193-254 N.N.N.255
255.255.255.224 8 nets N.N.N.0 N.N.N.1-30 N.N.N.31
3 bit Class C 30 N.N.N.32 N.N.N.33-62 N.N.N.63
11 bit Class B N.N.N.64 N.N.N.65-94 N.N.N.95
N.N.N.96 N.N.N.97-126 N.N.N.127
N.N.N.128 N.N.N.129-158 N.N.N.159
N.N.N.160 N.N.N.161-190 N.N.N.191
N.N.N.192 N.N.N.193-222 N.N.N.223
N.N.N.224 N.N.N.225-254 N.N.N.255
As you see, the first block you assigned is fully in the third /26 range.
The second block, starting with 144, is off somehow. I am a little unclear
if you wanted to give them a /26 or /27 block.
In addition, you need to make sure your router interface is visible on
both subnets. I'm assuming your configuration is something like this:
R1