Multihomed network - troubles with routing

Hi all,

I have a problem with a multihomed network, which I am
currently trying to configure. I have a domain controller
with 2 NICs - the first with IP 192.168.0.100 connecting
to an internal network. The second NIC has the IP address
192.168.1.10, and it connects via a network cable to a
router which provides Wireless access for notebooks
running XP. This router has IP 192.168.1.254. Another
port of the router connects to a cable modem for internet
access.

The Domain Controller is working as DHCP server.

Now, all hosts can connect to the Internet, and when I
connect a notebook through the wireless router, I can
ping the notebook from the domain server, but when I try
to ping the domain server from the notebook, I receive
either no reply (time-out), or, when I try to connect the
notebook directly to the NIC (192.168.1.10), I get the
message that the server is not available.

I have checked that DHCP is enabled and activated, but
nevertheless the problem remains.

Does anybody have a clue what could be wrong?

Thanks in advance.

Best regards,
L. Hummel, Denmark


L. Hummel

Is the DNS setting on the 192.168.1.x network pointing to the server
hosting your AD domain?

Rob Elder

"L. Hummel" <(E-Mail Removed)> wrote in message
news:6b2801c3e591$f2877c90$(E-Mail Removed)...
> Hi all,
>
> I have a problem with a multihomed network, which I am
> currently trying to configure. I have a domain controller
> with 2 NICs - the first with IP 192.168.0.100 connecting
> to an internal network. The second NIC has the IP address
> 192.168.1.10, and it connects via a network cable to a
> router which provides Wireless access for notebooks
> running XP. This router has IP 192.168.1.254. Another
> port of the router connects to a cable modem for internet
> access.
>
> The Domain Controller is working as DHCP server.
>
> Now, all hosts can connect to the Internet, and when I
> connect a notebook through the wireless router, I can
> ping the notebook from the domain server, but when I try
> to ping the domain server from the notebook, I receive
> either no reply (time-out), or, when I try to connect the
> notebook directly to the NIC (192.168.1.10), I get the
> message that the server is not available.
>
> I have checked that DHCP is enabled and activated, but
> nevertheless the problem remains.
>
> Does anybody have a clue what could be wrong?
>
> Thanks in advance.
>
> Best regards,
> L. Hummel, Denmark

Yes, it is.

L. Hummel


>-----Original Message-----
>Is the DNS setting on the 192.168.1.x network pointing
to the server
>hosting your AD domain?
>
>Rob Elder
>
>"L. Hummel" <(E-Mail Removed)> wrote in message
>news:6b2801c3e591$f2877c90$(E-Mail Removed)...
>> Hi all,
>>
>> I have a problem with a multihomed network, which I am
>> currently trying to configure. I have a domain
controller
>> with 2 NICs - the first with IP 192.168.0.100
connecting
>> to an internal network. The second NIC has the IP
address
>> 192.168.1.10, and it connects via a network cable to a
>> router which provides Wireless access for notebooks
>> running XP. This router has IP 192.168.1.254. Another
>> port of the router connects to a cable modem for
internet
>> access.
>>
>> The Domain Controller is working as DHCP server.
>>
>> Now, all hosts can connect to the Internet, and when I
>> connect a notebook through the wireless router, I can
>> ping the notebook from the domain server, but when I
try
>> to ping the domain server from the notebook, I receive
>> either no reply (time-out), or, when I try to connect
the
>> notebook directly to the NIC (192.168.1.10), I get the
>> message that the server is not available.
>>
>> I have checked that DHCP is enabled and activated, but
>> nevertheless the problem remains.
>>
>> Does anybody have a clue what could be wrong?
>>
>> Thanks in advance.
>>
>> Best regards,
>> L. Hummel, Denmark
>
>
>.
>

You need to configure static routes on your laptops so they can find the
192.168.0.x network:

route -p add 192.168.0.0 mask 255.255.255.0 192.168.1.10

Or - you may be able to configure this route on your router.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP


"L. Hummel" <(E-Mail Removed)> wrote in message
news:6b2801c3e591$f2877c90$(E-Mail Removed)...
> Hi all,
>
> I have a problem with a multihomed network, which I am
> currently trying to configure. I have a domain controller
> with 2 NICs - the first with IP 192.168.0.100 connecting
> to an internal network. The second NIC has the IP address
> 192.168.1.10, and it connects via a network cable to a
> router which provides Wireless access for notebooks
> running XP. This router has IP 192.168.1.254. Another
> port of the router connects to a cable modem for internet
> access.
>
> The Domain Controller is working as DHCP server.
>
> Now, all hosts can connect to the Internet, and when I
> connect a notebook through the wireless router, I can
> ping the notebook from the domain server, but when I try
> to ping the domain server from the notebook, I receive
> either no reply (time-out), or, when I try to connect the
> notebook directly to the NIC (192.168.1.10), I get the
> message that the server is not available.
>
> I have checked that DHCP is enabled and activated, but
> nevertheless the problem remains.
>
> Does anybody have a clue what could be wrong?
>
> Thanks in advance.
>
> Best regards,
> L. Hummel, Denmark

I have tried that - without luck

L. Hummel
>-----Original Message-----
>You need to configure static routes on your laptops so
they can find the
>192.168.0.x network:
>
> route -p add 192.168.0.0 mask 255.255.255.0
192.168.1.10
>
>Or - you may be able to configure this route on your
router.
>
>Doug Sherman
>MCSE Win2k/NT4.0, MCSA, MCP+I, MVP
>
>
>"L. Hummel" <(E-Mail Removed)> wrote in message
>news:6b2801c3e591$f2877c90$(E-Mail Removed)...
>> Hi all,
>>
>> I have a problem with a multihomed network, which I am
>> currently trying to configure. I have a domain
controller
>> with 2 NICs - the first with IP 192.168.0.100
connecting
>> to an internal network. The second NIC has the IP
address
>> 192.168.1.10, and it connects via a network cable to a
>> router which provides Wireless access for notebooks
>> running XP. This router has IP 192.168.1.254. Another
>> port of the router connects to a cable modem for
internet
>> access.
>>
>> The Domain Controller is working as DHCP server.
>>
>> Now, all hosts can connect to the Internet, and when I
>> connect a notebook through the wireless router, I can
>> ping the notebook from the domain server, but when I
try
>> to ping the domain server from the notebook, I receive
>> either no reply (time-out), or, when I try to connect
the
>> notebook directly to the NIC (192.168.1.10), I get the
>> message that the server is not available.
>>
>> I have checked that DHCP is enabled and activated, but
>> nevertheless the problem remains.
>>
>> Does anybody have a clue what could be wrong?
>>
>> Thanks in advance.
>>
>> Best regards,
>> L. Hummel, Denmark
>
>
>.
>

how does the notebook get the IP? Static or through DHCP? What scope, have
you set in DHCP, in 192.168.1.x subnet
or 192.168.0.x subnet? Did you configure BOOTP/DHCP Relay agent on the
router and enterted the IP helper address
as the DHCP server IP ?

Sharad


<(E-Mail Removed)> wrote in message
news:5aa501c3e5a4$f220a9d0$(E-Mail Removed)...
> Yes, it is.
>
> L. Hummel
>
>
> >-----Original Message-----
> >Is the DNS setting on the 192.168.1.x network pointing
> to the server
> >hosting your AD domain?
> >
> >Rob Elder
> >
> >"L. Hummel" <(E-Mail Removed)> wrote in message
> >news:6b2801c3e591$f2877c90$(E-Mail Removed)...
> >> Hi all,
> >>
> >> I have a problem with a multihomed network, which I am
> >> currently trying to configure. I have a domain
> controller
> >> with 2 NICs - the first with IP 192.168.0.100
> connecting
> >> to an internal network. The second NIC has the IP
> address
> >> 192.168.1.10, and it connects via a network cable to a
> >> router which provides Wireless access for notebooks
> >> running XP. This router has IP 192.168.1.254. Another
> >> port of the router connects to a cable modem for
> internet
> >> access.
> >>
> >> The Domain Controller is working as DHCP server.
> >>
> >> Now, all hosts can connect to the Internet, and when I
> >> connect a notebook through the wireless router, I can
> >> ping the notebook from the domain server, but when I
> try
> >> to ping the domain server from the notebook, I receive
> >> either no reply (time-out), or, when I try to connect
> the
> >> notebook directly to the NIC (192.168.1.10), I get the
> >> message that the server is not available.
> >>
> >> I have checked that DHCP is enabled and activated, but
> >> nevertheless the problem remains.
> >>
> >> Does anybody have a clue what could be wrong?
> >>
> >> Thanks in advance.
> >>
> >> Best regards,
> >> L. Hummel, Denmark
> >
> >
> >.
> >

Is the domain controller running Windows Server 2003? If so, and you
enabled routing through RRAS, you may have also enabled the basic firewall?

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

"L. Hummel" <(E-Mail Removed)> wrote in message
news:5feb01c3e5be$b6513c70$(E-Mail Removed)...
> I have tried that - without luck
>
> L. Hummel
> >-----Original Message-----
> >You need to configure static routes on your laptops so
> they can find the
> >192.168.0.x network:
> >
> > route -p add 192.168.0.0 mask 255.255.255.0
> 192.168.1.10
> >
> >Or - you may be able to configure this route on your
> router.
> >
> >Doug Sherman
> >MCSE Win2k/NT4.0, MCSA, MCP+I, MVP
> >
> >
> >"L. Hummel" <(E-Mail Removed)> wrote in message
> >news:6b2801c3e591$f2877c90$(E-Mail Removed)...
> >> Hi all,
> >>
> >> I have a problem with a multihomed network, which I am
> >> currently trying to configure. I have a domain
> controller
> >> with 2 NICs - the first with IP 192.168.0.100
> connecting
> >> to an internal network. The second NIC has the IP
> address
> >> 192.168.1.10, and it connects via a network cable to a
> >> router which provides Wireless access for notebooks
> >> running XP. This router has IP 192.168.1.254. Another
> >> port of the router connects to a cable modem for
> internet
> >> access.
> >>
> >> The Domain Controller is working as DHCP server.
> >>
> >> Now, all hosts can connect to the Internet, and when I
> >> connect a notebook through the wireless router, I can
> >> ping the notebook from the domain server, but when I
> try
> >> to ping the domain server from the notebook, I receive
> >> either no reply (time-out), or, when I try to connect
> the
> >> notebook directly to the NIC (192.168.1.10), I get the
> >> message that the server is not available.
> >>
> >> I have checked that DHCP is enabled and activated, but
> >> nevertheless the problem remains.
> >>
> >> Does anybody have a clue what could be wrong?
> >>
> >> Thanks in advance.
> >>
> >> Best regards,
> >> L. Hummel, Denmark
> >
> >
> >.
> >

I can see a couple of potential problems here. The first is the routing,
and the second separate problem is the multihomed DC.

The routing should work as long as the Internet router knows how to
reach the 192.168.0 subnet via the W2k machine. (By default it will try to
send this traffic to the Internet.) So you need a static route on this
router to forward 192.168.0 traffic to the W2k router. eg

192.168.0.0 255.255.255.0 192.168.1.10

The network looks like this?

Internet
|
public IP
router ------------wireless network IP?
192.168.1.254 dg?
|
192.168.1.10 dg 192.168.1.254
W2k
192.168.0.100 dg blank
|
workstations
192.168.0.x dg 192.168.0.100

If the wireless network clients use the router as their default gateway
and you add the static route to the router, you should be able to ping
between the local networks by IP.

The multihomed DC could give you assorted browsing and name resolution
problems. I would disable Netbios over TCP/IP on the 192.168.1.10 interface,
so that the DC is only seen on its 192.168.0 IP address. DNS can also be
affected if you have enabled dynamic DNS. Make sure DNS only listens on the
192.168.0.100 interface, so that it does not register multiple IPs for the
server.

"L. Hummel" <(E-Mail Removed)> wrote in message
news:5feb01c3e5be$b6513c70$(E-Mail Removed)...
> I have tried that - without luck
>
> L. Hummel
> >-----Original Message-----
> >You need to configure static routes on your laptops so
> they can find the
> >192.168.0.x network:
> >
> > route -p add 192.168.0.0 mask 255.255.255.0
> 192.168.1.10
> >
> >Or - you may be able to configure this route on your
> router.
> >
> >Doug Sherman
> >MCSE Win2k/NT4.0, MCSA, MCP+I, MVP
> >
> >
> >"L. Hummel" <(E-Mail Removed)> wrote in message
> >news:6b2801c3e591$f2877c90$(E-Mail Removed)...
> >> Hi all,
> >>
> >> I have a problem with a multihomed network, which I am
> >> currently trying to configure. I have a domain
> controller
> >> with 2 NICs - the first with IP 192.168.0.100
> connecting
> >> to an internal network. The second NIC has the IP
> address
> >> 192.168.1.10, and it connects via a network cable to a
> >> router which provides Wireless access for notebooks
> >> running XP. This router has IP 192.168.1.254. Another
> >> port of the router connects to a cable modem for
> internet
> >> access.
> >>
> >> The Domain Controller is working as DHCP server.
> >>
> >> Now, all hosts can connect to the Internet, and when I
> >> connect a notebook through the wireless router, I can
> >> ping the notebook from the domain server, but when I
> try
> >> to ping the domain server from the notebook, I receive
> >> either no reply (time-out), or, when I try to connect
> the
> >> notebook directly to the NIC (192.168.1.10), I get the
> >> message that the server is not available.
> >>
> >> I have checked that DHCP is enabled and activated, but
> >> nevertheless the problem remains.
> >>
> >> Does anybody have a clue what could be wrong?
> >>
> >> Thanks in advance.
> >>
> >> Best regards,
> >> L. Hummel, Denmark
> >
> >
> >.
> >

Yes, indeed the basic firewall was activated - when I
unchecked it, everything worked perfectly. Great!

Thanks very much for your help.

>-----Original Message-----
>Is the domain controller running Windows Server 2003?
If so, and you
>enabled routing through RRAS, you may have also enabled
the basic firewall?
>
>Doug Sherman
>MCSE Win2k/NT4.0, MCSA, MCP+I, MVP
>
>"L. Hummel" <(E-Mail Removed)> wrote in message
>news:5feb01c3e5be$b6513c70$(E-Mail Removed)...
>> I have tried that - without luck
>>
>> L. Hummel
>> >-----Original Message-----
>> >You need to configure static routes on your laptops so
>> they can find the
>> >192.168.0.x network:
>> >
>> > route -p add 192.168.0.0 mask 255.255.255.0
>> 192.168.1.10
>> >
>> >Or - you may be able to configure this route on your
>> router.
>> >
>> >Doug Sherman
>> >MCSE Win2k/NT4.0, MCSA, MCP+I, MVP
>> >
>> >
>> >"L. Hummel" <(E-Mail Removed)> wrote in message
>> >news:6b2801c3e591$f2877c90$(E-Mail Removed)...
>> >> Hi all,
>> >>
>> >> I have a problem with a multihomed network, which I
am
>> >> currently trying to configure. I have a domain
>> controller
>> >> with 2 NICs - the first with IP 192.168.0.100
>> connecting
>> >> to an internal network. The second NIC has the IP
>> address
>> >> 192.168.1.10, and it connects via a network cable
to a
>> >> router which provides Wireless access for notebooks
>> >> running XP. This router has IP 192.168.1.254.
Another
>> >> port of the router connects to a cable modem for
>> internet
>> >> access.
>> >>
>> >> The Domain Controller is working as DHCP server.
>> >>
>> >> Now, all hosts can connect to the Internet, and
when I
>> >> connect a notebook through the wireless router, I
can
>> >> ping the notebook from the domain server, but when I
>> try
>> >> to ping the domain server from the notebook, I
receive
>> >> either no reply (time-out), or, when I try to
connect
>> the
>> >> notebook directly to the NIC (192.168.1.10), I get
the
>> >> message that the server is not available.
>> >>
>> >> I have checked that DHCP is enabled and activated,
but
>> >> nevertheless the problem remains.
>> >>
>> >> Does anybody have a clue what could be wrong?
>> >>
>> >> Thanks in advance.
>> >>
>> >> Best regards,
>> >> L. Hummel, Denmark
>> >
>> >
>> >.
>> >
>
>
>.
>

Hi...

Well, the troubles didn't completely stop, although I am
now able to ping the NIC from the workstation. I now have
a different problem. First, the network is Windows Server
2003 based, and all workstations and notebooks run either
W2K or XP Pro. An illustration of the topology of the
network is shown here:

WWW (through T1 line)
|
| Notebooks... 192.168.1.x
| |
| Antenna
| |
Wireless Router/HUB 192.168.1.254
| |
| |
| Hub---------- Workstations (group 2)
| 192.168.1.x
| (dg 192.168.1.10)
|
|
|
| 192.168.1.x
192.168.1.10 |
Domain Controller/DHCP Server (dg 192.168.1.254)
192.168.0.100 |
| 192.168.0.x
|
|
|
|
Workstations (group 1) 192.168.0.x
(dg 192.168.0.100)

On the server, the NIC with IP 192.168.1.10 has been
configured as a public interface connected to the
Internet, and NAT has been enabled.

The NIC with IP 192.168.0.100 has been configured as a
private interface connected to a private network.

First, I can connect to the WWW from all workstations and
notebooks (although I can only connect the notebooks via
the HUB in the Wireless Adapter, as the wireless part
still remains to be configured, which I will do later).

Now, when I connect a PC to the HUB in the Wireless
adapter (group 2), It receives an IP via DHCP as it
should, and I can "ping" the NIC 192.168.1.10 without
problems.

Furthermore, from any workstation in group 1, I can also
ping the IP, which the workstation has received from
DHCP, so this is also Ok.

However, the problem arises when I try to "ping" any IP
in the 192.168.0.x subnet (group 1) from any workstation
in group 2.

So, the PCs in group 1 can all "see" the PCs in group 2,
while the opposite is not the case.

Does anybody know what the problem can be?

Thanks in advance.

L. Hummel
>-----Original Message-----
> I can see a couple of potential problems here. The
first is the routing,
>and the second separate problem is the multihomed DC.
>
> The routing should work as long as the Internet
router knows how to
>reach the 192.168.0 subnet via the W2k machine. (By
default it will try to
>send this traffic to the Internet.) So you need a static
route on this
>router to forward 192.168.0 traffic to the W2k
router. eg
>
>192.168.0.0 255.255.255.0 192.168.1.10
>
> The network looks like this?
>
> Internet
> |
> public IP
> router ------------wireless network IP?
>
192.168.1.254 dg?
> |
> 192.168.1.10 dg 192.168.1.254
> W2k
> 192.168.0.100 dg blank
> |
> workstations
> 192.168.0.x dg 192.168.0.100
>
> If the wireless network clients use the router as
their default gateway
>and you add the static route to the router, you should
be able to ping
>between the local networks by IP.
>
> The multihomed DC could give you assorted browsing
and name resolution
>problems. I would disable Netbios over TCP/IP on the
192.168.1.10 interface,
>so that the DC is only seen on its 192.168.0 IP
address. DNS can also be
>affected if you have enabled dynamic DNS. Make sure DNS
only listens on the
>192.168.0.100 interface, so that it does not register
multiple IPs for the
>server.
>
>"L. Hummel" <(E-Mail Removed)> wrote in message
>news:5feb01c3e5be$b6513c70$(E-Mail Removed)...
>> I have tried that - without luck
>>
>> L. Hummel
>> >-----Original Message-----
>> >You need to configure static routes on your laptops so
>> they can find the
>> >192.168.0.x network:
>> >
>> > route -p add 192.168.0.0 mask 255.255.255.0
>> 192.168.1.10
>> >
>> >Or - you may be able to configure this route on your
>> router.
>> >
>> >Doug Sherman
>> >MCSE Win2k/NT4.0, MCSA, MCP+I, MVP
>> >
>> >
>> >"L. Hummel" <(E-Mail Removed)> wrote in message
>> >news:6b2801c3e591$f2877c90$(E-Mail Removed)...
>> >> Hi all,
>> >>
>> >> I have a problem with a multihomed network, which I
am
>> >> currently trying to configure. I have a domain
>> controller
>> >> with 2 NICs - the first with IP 192.168.0.100
>> connecting
>> >> to an internal network. The second NIC has the IP
>> address
>> >> 192.168.1.10, and it connects via a network cable
to a
>> >> router which provides Wireless access for notebooks
>> >> running XP. This router has IP 192.168.1.254.
Another
>> >> port of the router connects to a cable modem for
>> internet
>> >> access.
>> >>
>> >> The Domain Controller is working as DHCP server.
>> >>
>> >> Now, all hosts can connect to the Internet, and
when I
>> >> connect a notebook through the wireless router, I
can
>> >> ping the notebook from the domain server, but when I
>> try
>> >> to ping the domain server from the notebook, I
receive
>> >> either no reply (time-out), or, when I try to
connect
>> the
>> >> notebook directly to the NIC (192.168.1.10), I get
the
>> >> message that the server is not available.
>> >>
>> >> I have checked that DHCP is enabled and activated,
but
>> >> nevertheless the problem remains.
>> >>
>> >> Does anybody have a clue what could be wrong?
>> >>
>> >> Thanks in advance.
>> >>
>> >> Best regards,
>> >> L. Hummel, Denmark
>> >
>> >
>> >.
>> >
>
>
>.
>