Arp question

Dear Experts,

I am working with 2 terminal servers 2003, fully up to date. Once in a while
I cannot ping or connect to 1 of the terminal servers. when I type ARP -a I
see some dynamic addresses and some invalid addresses.
Internet-address Fysical address Type
172.16.20.241 00-00-00-00-00-00 Invalid

what can be the cause of the invalid addresses?

when I add the address as static, it works ok.

Hope you can help me.

Kind regards,

Evert

Have you checked your gateway router or switch (if you are using a layer 3
switch) for a static arp entry?

"E. van Zanten" wrote:

> Dear Experts,
>
> I am working with 2 terminal servers 2003, fully up to date. Once in a while
> I cannot ping or connect to 1 of the terminal servers. when I type ARP -a I
> see some dynamic addresses and some invalid addresses.
> Internet-address Fysical address Type
> 172.16.20.241 00-00-00-00-00-00 Invalid
>
> what can be the cause of the invalid addresses?
>
> when I add the address as static, it works ok.
>
> Hope you can help me.
>
> Kind regards,
>
> Evert
>
>
>

Also, is this only happening from your computer? If so try clearing your arp
cache.
netsh interface ip delete arpcache

"E. van Zanten" wrote:

> Dear Experts,
>
> I am working with 2 terminal servers 2003, fully up to date. Once in a while
> I cannot ping or connect to 1 of the terminal servers. when I type ARP -a I
> see some dynamic addresses and some invalid addresses.
> Internet-address Fysical address Type
> 172.16.20.241 00-00-00-00-00-00 Invalid
>
> what can be the cause of the invalid addresses?
>
> when I add the address as static, it works ok.
>
> Hope you can help me.
>
> Kind regards,
>
> Evert
>
>
>

the router is a cisco2610. which entry should be made then?
I cannot ping to the router and an other win2003 server
I can ping all the other servers

kind regards,

Evert

"CS1031" <(E-Mail Removed)> schreef in bericht
news:3F75F9FE-36A2-49AA-8FA8-(E-Mail Removed)...
> Have you checked your gateway router or switch (if you are using a layer 3
> switch) for a static arp entry?
>
> "E. van Zanten" wrote:
>
>> Dear Experts,
>>
>> I am working with 2 terminal servers 2003, fully up to date. Once in a
>> while
>> I cannot ping or connect to 1 of the terminal servers. when I type ARP -a
>> I
>> see some dynamic addresses and some invalid addresses.
>> Internet-address Fysical address Type
>> 172.16.20.241 00-00-00-00-00-00 Invalid
>>
>> what can be the cause of the invalid addresses?
>>
>> when I add the address as static, it works ok.
>>
>> Hope you can help me.
>>
>> Kind regards,
>>
>> Evert
>>
>>
>>

after clearing up the arpcache I still cannot ping my router and the other
server

rgds,

Evert

"CS1031" <(E-Mail Removed)> schreef in bericht
news:4B16876C-0251-4737-9A6A-(E-Mail Removed)...
> Also, is this only happening from your computer? If so try clearing your
> arp
> cache.
> netsh interface ip delete arpcache
>
> "E. van Zanten" wrote:
>
>> Dear Experts,
>>
>> I am working with 2 terminal servers 2003, fully up to date. Once in a
>> while
>> I cannot ping or connect to 1 of the terminal servers. when I type ARP -a
>> I
>> see some dynamic addresses and some invalid addresses.
>> Internet-address Fysical address Type
>> 172.16.20.241 00-00-00-00-00-00 Invalid
>>
>> what can be the cause of the invalid addresses?
>>
>> when I add the address as static, it works ok.
>>
>> Hope you can help me.
>>
>> Kind regards,
>>
>> Evert
>>
>>
>>

Ok, let me better understand this. Are you the admin there? If so, what
kindof network are you on? Are you getting the right DHCP address to your
computer? It almost sounds like you have a different subnet mask or
something. I mean if you cant ping your router thats a problem. If you cant
ping other servers on your network that is a problem. What are your IP
settings? What are the IP settings of your servers and router?

"E. van Zanten" wrote:

> the router is a cisco2610. which entry should be made then?
> I cannot ping to the router and an other win2003 server
> I can ping all the other servers
>
> kind regards,
>
> Evert
>
> "CS1031" <(E-Mail Removed)> schreef in bericht
> news:3F75F9FE-36A2-49AA-8FA8-(E-Mail Removed)...
> > Have you checked your gateway router or switch (if you are using a layer 3
> > switch) for a static arp entry?
> >
> > "E. van Zanten" wrote:
> >
> >> Dear Experts,
> >>
> >> I am working with 2 terminal servers 2003, fully up to date. Once in a
> >> while
> >> I cannot ping or connect to 1 of the terminal servers. when I type ARP -a
> >> I
> >> see some dynamic addresses and some invalid addresses.
> >> Internet-address Fysical address Type
> >> 172.16.20.241 00-00-00-00-00-00 Invalid
> >>
> >> what can be the cause of the invalid addresses?
> >>
> >> when I add the address as static, it works ok.
> >>
> >> Hope you can help me.
> >>
> >> Kind regards,
> >>
> >> Evert
> >>
> >>
> >>
>
>
>

here is a short overview

ntbr04 (server w2k) 172.16.20.204, this server can ping to everything,
including 172.16.20.207
ntbr07 (server w2k3) 172.16.20.207 can ping to everything, except
172.16.20.241 and 172.16.20.208
ntbr08 (server w2k3) 172.16.20.208 cannot ping to 172.16.20.207
ilro01 (Router, Cisco2610) 172.16.20.241 can ping everything, except
172.16.20.207
vpnbr (Router, Nortel1010) 172.16.20.242 can ping everything, including
172.16.20.207
fwbr (Router, Nortel1010) 172.16.20.244 can ping everything, except
172.16.20.207

ntbr07 and ntbr08 are terminal servers, load balanced with ip address
172.16.20.210. arp entrys are made in de cisco and nortels
all ip addresses are static, with subnetmask 255.255.255.0 and default
gateway 172.16.20.241

rgds,

Evert

"CS1031" <(E-Mail Removed)> schreef in bericht
news:4B5DB7C8-47DF-4D8D-A36B-(E-Mail Removed)...
> Ok, let me better understand this. Are you the admin there? If so, what
> kindof network are you on? Are you getting the right DHCP address to your
> computer? It almost sounds like you have a different subnet mask or
> something. I mean if you cant ping your router thats a problem. If you
> cant
> ping other servers on your network that is a problem. What are your IP
> settings? What are the IP settings of your servers and router?
>
> "E. van Zanten" wrote:
>
>> the router is a cisco2610. which entry should be made then?
>> I cannot ping to the router and an other win2003 server
>> I can ping all the other servers
>>
>> kind regards,
>>
>> Evert
>>
>> "CS1031" <(E-Mail Removed)> schreef in bericht
>> news:3F75F9FE-36A2-49AA-8FA8-(E-Mail Removed)...
>> > Have you checked your gateway router or switch (if you are using a
>> > layer 3
>> > switch) for a static arp entry?
>> >
>> > "E. van Zanten" wrote:
>> >
>> >> Dear Experts,
>> >>
>> >> I am working with 2 terminal servers 2003, fully up to date. Once in a
>> >> while
>> >> I cannot ping or connect to 1 of the terminal servers. when I type
>> >> ARP -a
>> >> I
>> >> see some dynamic addresses and some invalid addresses.
>> >> Internet-address Fysical address Type
>> >> 172.16.20.241 00-00-00-00-00-00 Invalid
>> >>
>> >> what can be the cause of the invalid addresses?
>> >>
>> >> when I add the address as static, it works ok.
>> >>
>> >> Hope you can help me.
>> >>
>> >> Kind regards,
>> >>
>> >> Evert
>> >>
>> >>
>> >>
>>
>>
>>

Well the first thing I would do is go back to those servers, check all IP
settings including TCP/IP filtering. Make sure everything is on the same
subnet and there are no software firewalls enabled. Also, check the host file
on each server and make sure there are no hard coded wrong IPs accociated
with those server names.

"E. van Zanten" wrote:

> here is a short overview
>
> ntbr04 (server w2k) 172.16.20.204, this server can ping to everything,
> including 172.16.20.207
> ntbr07 (server w2k3) 172.16.20.207 can ping to everything, except
> 172.16.20.241 and 172.16.20.208
> ntbr08 (server w2k3) 172.16.20.208 cannot ping to 172.16.20.207
> ilro01 (Router, Cisco2610) 172.16.20.241 can ping everything, except
> 172.16.20.207
> vpnbr (Router, Nortel1010) 172.16.20.242 can ping everything, including
> 172.16.20.207
> fwbr (Router, Nortel1010) 172.16.20.244 can ping everything, except
> 172.16.20.207
>
> ntbr07 and ntbr08 are terminal servers, load balanced with ip address
> 172.16.20.210. arp entrys are made in de cisco and nortels
> all ip addresses are static, with subnetmask 255.255.255.0 and default
> gateway 172.16.20.241
>
> rgds,
>
> Evert
>
> "CS1031" <(E-Mail Removed)> schreef in bericht
> news:4B5DB7C8-47DF-4D8D-A36B-(E-Mail Removed)...
> > Ok, let me better understand this. Are you the admin there? If so, what
> > kindof network are you on? Are you getting the right DHCP address to your
> > computer? It almost sounds like you have a different subnet mask or
> > something. I mean if you cant ping your router thats a problem. If you
> > cant
> > ping other servers on your network that is a problem. What are your IP
> > settings? What are the IP settings of your servers and router?
> >
> > "E. van Zanten" wrote:
> >
> >> the router is a cisco2610. which entry should be made then?
> >> I cannot ping to the router and an other win2003 server
> >> I can ping all the other servers
> >>
> >> kind regards,
> >>
> >> Evert
> >>
> >> "CS1031" <(E-Mail Removed)> schreef in bericht
> >> news:3F75F9FE-36A2-49AA-8FA8-(E-Mail Removed)...
> >> > Have you checked your gateway router or switch (if you are using a
> >> > layer 3
> >> > switch) for a static arp entry?
> >> >
> >> > "E. van Zanten" wrote:
> >> >
> >> >> Dear Experts,
> >> >>
> >> >> I am working with 2 terminal servers 2003, fully up to date. Once in a
> >> >> while
> >> >> I cannot ping or connect to 1 of the terminal servers. when I type
> >> >> ARP -a
> >> >> I
> >> >> see some dynamic addresses and some invalid addresses.
> >> >> Internet-address Fysical address Type
> >> >> 172.16.20.241 00-00-00-00-00-00 Invalid
> >> >>
> >> >> what can be the cause of the invalid addresses?
> >> >>
> >> >> when I add the address as static, it works ok.
> >> >>
> >> >> Hope you can help me.
> >> >>
> >> >> Kind regards,
> >> >>
> >> >> Evert
> >> >>
> >> >>
> >> >>
> >>
> >>
> >>
>
>
>

In news:newscache$dyn33j$n012$(E-Mail Removed),
E. van Zanten <(E-Mail Removed)> stated, which I commented on below:
> Dear Experts,
>
> I am working with 2 terminal servers 2003, fully up to date. Once in
> a while I cannot ping or connect to 1 of the terminal servers. when I
> type ARP -a I see some dynamic addresses and some invalid addresses.
> Internet-address Fysical address Type
> 172.16.20.241 00-00-00-00-00-00 Invalid
>
> what can be the cause of the invalid addresses?
>
> when I add the address as static, it works ok.
>
> Hope you can help me.
>
> Kind regards,
>
> Evert

I hate to state the obvious, and not to be facetious about it, but did you
check the NIC wires? Could be a simple bad wire.

Quick story: One time many years ago in the mid to late 90's, I was chasing
this problem as to why DFS running on NT4 at the time, wouldn't work
properly. Nothing else appeared wrong, and pretty much everything appeared
functional, no Event log errors, etc, but users complaining the DFS root
wouldn't work, meaning it appeard blank when they clicked on their mapped
drive to the DFS root. After two months of trying to figure out what was
happening, I was serendipitiously rearranging and trying to re-map and doc
all the ports and wires on the switch, and I found one connector had a loose
wire. I traced it back and found it was going to the server hosting DFS. I
changed out the wire and wouldn't you know it, DFS worked fine! One thing
that hurt is their is no notification you can set in the Systray to notify
you the cable is unplugged on NT4 like you can these days.

After that ordeal, now I always check wiring first... :-)

--
Ace
Innovative IT Concepts, Inc
Willow Grove, PA

This posting is provided "AS-IS" with no warranties or guarantees and
confers no rights.

Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
Microsoft MVP - Directory Services
Microsoft Certified Trainer

Having difficulty reading or finding responses to your post?
Instead of the website you're using, I suggest to use OEx (Outlook Express
or any other newsreader), and configure a news account, pointing to
news.microsoft.com. This is a direct link to the Microsoft Public
Newsgroups. It is FREE and requires NO ISP's Usenet account. OEx allows you
to easily find, track threads, cross-post, sort by date, poster's name,
watched threads or subject.
It's easy:

How to Configure OEx for Internet News
http://support.microsoft.com/?id=171164

Infinite Diversities in Infinite Combinations
Assimilation Imminent. Resistance is Futile
"Very funny Scotty. Now, beam down my clothes."

The only constant in life is change...

Your network card is not being recognized - physical address refers to the
MAC address. - Anthony's suggestion is worthwhile.

"Ace Fekay [MVP]" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> In news:newscache$dyn33j$n012$(E-Mail Removed),
> E. van Zanten <(E-Mail Removed)> stated, which I commented on below:
>> Dear Experts,
>>
>> I am working with 2 terminal servers 2003, fully up to date. Once in
>> a while I cannot ping or connect to 1 of the terminal servers. when I
>> type ARP -a I see some dynamic addresses and some invalid addresses.
>> Internet-address Fysical address Type
>> 172.16.20.241 00-00-00-00-00-00 Invalid
>>
>> what can be the cause of the invalid addresses?
>>
>> when I add the address as static, it works ok.
>>
>> Hope you can help me.
>>
>> Kind regards,
>>
>> Evert
>
> I hate to state the obvious, and not to be facetious about it, but did you
> check the NIC wires? Could be a simple bad wire.
>
> Quick story: One time many years ago in the mid to late 90's, I was
> chasing this problem as to why DFS running on NT4 at the time, wouldn't
> work properly. Nothing else appeared wrong, and pretty much everything
> appeared functional, no Event log errors, etc, but users complaining the
> DFS root wouldn't work, meaning it appeard blank when they clicked on
> their mapped drive to the DFS root. After two months of trying to figure
> out what was happening, I was serendipitiously rearranging and trying to
> re-map and doc all the ports and wires on the switch, and I found one
> connector had a loose wire. I traced it back and found it was going to the
> server hosting DFS. I changed out the wire and wouldn't you know it, DFS
> worked fine! One thing that hurt is their is no notification you can set
> in the Systray to notify you the cable is unplugged on NT4 like you can
> these days.
>
> After that ordeal, now I always check wiring first... :-)
>
> --
> Ace
> Innovative IT Concepts, Inc
> Willow Grove, PA
>
> This posting is provided "AS-IS" with no warranties or guarantees and
> confers no rights.
>
> Ace Fekay, MCSE 2003 & 2000, MCSA 2003 & 2000, MCSE+I, MCT, MVP
> Microsoft MVP - Directory Services
> Microsoft Certified Trainer
>
> Having difficulty reading or finding responses to your post?
> Instead of the website you're using, I suggest to use OEx (Outlook Express
> or any other newsreader), and configure a news account, pointing to
> news.microsoft.com. This is a direct link to the Microsoft Public
> Newsgroups. It is FREE and requires NO ISP's Usenet account. OEx allows
> you to easily find, track threads, cross-post, sort by date, poster's
> name, watched threads or subject.
> It's easy:
>
> How to Configure OEx for Internet News
> http://support.microsoft.com/?id=171164
>
> Infinite Diversities in Infinite Combinations
> Assimilation Imminent. Resistance is Futile
> "Very funny Scotty. Now, beam down my clothes."
>
> The only constant in life is change...
>
>