Config for a Cisco 2500 with cable modem?
jwa...@home.com
Internet through my Cisco 2501 which has 2 ethernet ports. What I was
planning in doing is plugging the cable modem to EO and plugging the
hub into E1.
My questions concerns the configuration of E0 which will have the
cable modem plugged in. Do I set the IP address and subnet mask to
that of my cable modem (which has a static IP address) on the E0
interface? Where do I plug in the DNS servers IP info?
On the E1 interface I was planning on a configuration of 192.168.1.254
with a mask of 255.255.255.0. What else is needed on the config of
interface E1 to make sure traffic is passed through to E0 (and the
Internet)?
Finally, I was planning on assigning my PCs IP addresses in the
192.168.1.x range. Should the default gateway be 192.168.1.254 on my
PCs?
Thanks,
Jeff
John Hardman
--
John Hardman, MCSE+I, CCNA
ArrisTech/CCS-IS SysAdmin
<jwa...@home.com> wrote in message
news:tgef5skrpn6lvrndh...@4ax.com...
> I would like to set up my cable modem (through @Home) to access the
> Internet through my Cisco 2501 which has 2 ethernet ports. What I was
> planning in doing is plugging the cable modem to EO and plugging the
> hub into E1.
If you have a 2501, you do not have two ethernet ports, you have one
ethernet and two serial ports. I will assume that you really have a 2514 for
the rest of your questions since the 2514 has two ethernet ports.
> My questions concerns the configuration of E0 which will have the
> cable modem plugged in. Do I set the IP address and subnet mask to
> that of my cable modem (which has a static IP address) on the E0
> interface? Where do I plug in the DNS servers IP info?
Unless you have @Work then you really do not have a static IP. @Home uses a
dynamic IP assignment, however it is only there to allow them to renumber
their network, which doesn't happen offten, so for your needs it is a
"static" IP. But if they renumber, your IP will change and you will need to
hook a PC and use DHCP to get your new address info.
Now your terms, "Do I set the IP address and subnet mask to that of my cable
modem". Your cable modem has a private IP, not a public IP, and frankly I
doubt you have it. However @Home has assigned you a public IP for your PC,
and that is the IP in question here. Just so we are clear...
You will need to config your e0 int with the public IP and subnet mask. You
will also need a static default route to that int, i.e. up route 0.0.0.0
0.0.0.0 (public IP)
Your DNS info goes on your PC as you really are not likely to need name
resolution on the router unless you intend to do a lot of pinging/telneting
by name on the router.
> On the E1 interface I was planning on a configuration of 192.168.1.254
> with a mask of 255.255.255.0. What else is needed on the config of
> interface E1 to make sure traffic is passed through to E0 (and the
> Internet)?
>
> Finally, I was planning on assigning my PCs IP addresses in the
> 192.168.1.x range. Should the default gateway be 192.168.1.254 on my
> PCs?
Yes this is correct. You will also need to run NAT and it wouldn't be a bad
idea to use access list too. Check the Cisco web site for more info on NAT
and access-lists.
From the type of questions you are asking it sounds like you are some what
green with networking. There is a lot to learn, be careful and pick up a
book. You are in for more work than you think you are ;-)
HTH
> Thanks,
> Jeff
jwa...@home.com
Thanks for the reply. Sorry about the errors as well. The router is a
2514 and not a 2501 as you pointed out.
For @Home, the IP address can be made static by entering the info into
the network setup in NT or Win9x. Being that I will not be able to
make the IP address static since I am plugging the cable modem into
the router how do I deal with a dynamic IP address when configuring
the E0 interface? Must I change the configuration of the E0 interface
everytime the cable modem is supplied with a new IP address?
(technically I should hang on to the IP address that @Home's DHCP
server supplied but I get the occassional rouge DHCP server out there
that supplies me with a bogus 192.168..x.x address)
What IOS ver supports NAT for 2514? And I will most definitely create
access-lists..
Thanks,
Jeff
mgui...@rci.rogers.com
the "static" properties in Windows. The IP address you have is not
static as it is not reserved for your PC. What you are doing
is "hardcoding" the dynamic address for your PC. You are telling your
PC not to go out and obtain an address from a DHCP server.
If you "hardcode" your dynamic address and @home renumbers, your
address will no longer be valid. In this case you will have to connect
a PC to the cable modem and request a new address from a DHCP server,
then re-enter the new address info into the "static" mapping. The same
goes for a router. You "hardcode" your assigned address into the
ethernet interface. You will not need to worry about rouge DHCP
servers as your ethernet interface is not asking for an address. But
if @home renumbers you will have to connect a PC to the cable modem and
get your new address then change it on the ethernet interface on the
router. With luck @home will not renumber too often.
Good luck, have fun.
Sent via Deja.com http://www.deja.com/
Before you buy.
Dennis Hess
Also, @Home network does give out some static ip's. I imagine they'll be
stopping that eventually though.
D
"John Hardman" <johnhardman1@NO_SPAM_home.net> wrote in message
news:XOP54.3746$EF6....@news.rdc1.az.home.com...
> > Thanks,
> > Jeff
>
>
John Hardman
See the other reply in regards to static verus dynamic IPs on @Home.
I know what you mean about the stray 192.168.x.x addresses. Most people do
not know that @Home is actually using a private network that they are
routing public IPs over. I discovered this quite be accident. I picked up a
trial copy of a network ping/SNMP discovery tool. At that time I was using
Win2K with connection sharing, and low and behold I found all kinds of
192.168.x.x hosts with some pretty wild SNMP info. The cable modem is also
on a private net 10.x.x.x.
For NAT you will need a 11.x IP Plus image for a IP only 12.0 image.
I wouldn't worry about having to change your IP too offten, I have had to do
it two times in 18 months, and one of those was a move from one house to
another, so in reality there was one renumber.
HTH
--
John Hardman, MCSE+I, CCNA
ArrisTech/CCS-IS SysAdmin
<jwa...@home.com> wrote in message
news:pq1g5sg240gqtvhav...@4ax.com...
> John,
>
> Thanks for the reply. Sorry about the errors as well. The router is a
> 2514 and not a 2501 as you pointed out.
>
> For @Home, the IP address can be made static by entering the info into
> the network setup in NT or Win9x. Being that I will not be able to
> make the IP address static since I am plugging the cable modem into
> the router how do I deal with a dynamic IP address when configuring
> the E0 interface? Must I change the configuration of the E0 interface
> everytime the cable modem is supplied with a new IP address?
> (technically I should hang on to the IP address that @Home's DHCP
> server supplied but I get the occassional rouge DHCP server out there
> that supplies me with a bogus 192.168..x.x address)
>
> What IOS ver supports NAT for 2514? And I will most definitely create
> access-lists..
>
> Thanks,
> Jeff
>
jwa...@home.com
How would I go about upgrading memory on my 2514? I would like to move
to the 12.0 12.0(4)T IOS version but it takes up 26mb.
Thanks,
Jeff
John Hardman
Actually you would want 12.0(6) which is about 5.6MB, so you will need
8/16MB flash to run it. Keep an eye on eBay, there are flash simms for the
2500/4500/5100 there from time to time.
BTW I would check that 26mb size, that sounds way too large... how would you
put it on a router that maxs at 16MB DRAM and 16MB Flash?
HTH
--
John Hardman, MCSE+I, CCNA
ArrisTech/CCS-IS SysAdmin
<jwa...@home.com> wrote in message
news:0qqh5ss41aen4gfbm...@4ax.com...
jwa...@home.com
System flash directory:
File Length Name/status
1 2662440 c1700-y-mz.120-4.T
[2662504 bytes used, 1531800 available, 4194304 total
John Hardman
From what I see here you have image from a 1720 not a 2514, correct me if I
am wrong.... Didn't know that would run... interesting. The 12.0(6) image
for the 2500 series is apx 5.6MB though.
Also, it shows a size of apx 2.6MB not 26MB. With a total of 4MB flash, not
enough for 2500 image of 12.
BTW, just out of curiosity, port a sh ver for me, I would like to see it.
HTH
--
John Hardman, MCSE+I, CCNA
ArrisTech/CCS-IS SysAdmin
<jwa...@home.com> wrote in message
news:2chi5so46849c7vtp...@4ax.com...
routerwanter
just for replacing NIC's people upgrade to new computers all the time, since
a lot of new computers come with NIC's installed there would certainly be a
new NIC. I can only assume that you meant the MAC address since with the
new docsis standard they are able to tell not only if the MAC changes, but
how many MAC's the modem has noticed traveling through it to the internet.
(they charge for add'l IP's) since the only product here is bandwidth, if
you don't pay for additional computers on the internet, you are stealing the
product. Now I just work for one cable company so I can only tell you how
we do it. If we notice several mac's changing frequently, and alot of high
activity, then we will monitor the account, as per your user agreement. by
monitor I don't meant that we can actually watch WHAT goes in and out, only
how much. I see alot of people in misc. warez groups etc bragging about
running their cable modem for FTP servers, I can only suggest that they be a
little more discreet. I am a service tech, so don't take anything I say to
your lawyer as if it is "company mandates" I am just saying this as what I
have heard from the security, and TOS dept.'s
TM in Nashville <hal-...@home.com> wrote in message
news:hKNZOBMvqtfM4c...@4ax.com...
> Hrm...I have heard via a couple of friends with cable modems, that if
> they detect you using a different NIC than the one @Home provides
> during installation of the service, that they will cancel your
> account.
>
> Now, I would say that this would include connecting a router directly
> to the cable modem.
>
> Any similar experiences by anyone?
>
> Tracy Miller (Nashville)
TM in Nashville
John Hardman
more than one PC at any one time thru the connection. Granted this is a bit
of a gray area, as any of my PCs could access the connection at the same
time.
My primary motivation for putting a router on the cable modem is to gain
additional hands on real world configuration expeirence on Cisco routers. I
have learned a lot about NAT/PAT and access lists from having it here. It
also helps keep the snoops out of my PC.
--
John Hardman, MCSE+I, CCNA
ArrisTech/CCS-IS SysAdmin
"routerwanter" <jegr...@gemnetworks.com> wrote in message
news:83c96g$ena$1...@nntp8.atl.mindspring.net...
jwa...@home.com
work. I will post the flash info from the 2514 later tonight.
Here is the sh ver info:
Cisco Internetwork Operating System Software
IOS (tm) C1700 Software (C1700-Y-M), Version 12.0(4)T, RELEASE
SOFTWARE (fc1)
Copyright (c) 1986-1999 by cisco Systems, Inc.
Compiled Wed 28-Apr-99 14:34 by kpma
ROM: System Bootstrap, Version 12.0(3)T, RELEASE SOFTWARE (fc1)
uptime is 6 days, 16 hours, 5 minutes
System restarted by power-on
System image file is "flash:c1700-y-mz.120-4.T"
cisco 1720 (MPC860) processor (revision 0x101) with 12288K/4096K bytes
of memory
.
Processor board ID JAD03241314 (3402234190), with hardware revision
0000
M860 processor: part number 0, mask 32
Bridging software.
X.25 software, Version 3.0.0.
1 FastEthernet/IEEE 802.3 interface(s)
1 Serial network interface(s)
WIC T1-DSU
32K bytes of non-volatile configuration memory.
4096K bytes of processor board System flash (Read/Write)
Configuration register is 0x2102