Underscores in URL's

  • Thread starter Thread starter Russ
  • Start date Start date
R

Russ

I have recently created a DNS entry with an underscore in
it. This entry resolves to the ip address of a database
server which is browsable by clients. Certain clients can
access the url others cant. I have tried from 2 different
machines both using ie 5.5 with sp2, one can access it the
other cannot. Is dns having a problem with the underscore?


thanks...
 
r> But why does it work on some machines but not others?

You tell us. You are the one with the error messages from those machines in
front of you. What do they actually _say_ ?
 
In
Jonathan de Boyne Pollard said:
r> But why does it work on some machines but not others?

You tell us. You are the one with the error messages from those
machines in front of you. What do they actually _say_ ?
Click to expand...

Actually I've seen issues (5509 errors) with underscores, spaces and a
variety of other characters except dashes used in DNS names. As for URLs,
those underscores could be from a virtual directory or folder under the
website root.

http://www.experts-exchange.com/Networking/WinNT_Networking/Q_10130539.html

Although, underscores are valid characters, as noted here:
http://support.microsoft.com/?id=288176
I've found removing them eliminates the 5509 errors. Why? Don't know, but it
works.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory
 
AF> Although, underscores are valid characters, as noted here:
AF> http://support.microsoft.com/?id=288176
AF> I've found removing them eliminates the 5509 errors. Why?
AF> Don't know, but it works.

Possibly because, as that article says, the server is checking
the domain names given in the update messages and rejecting those
that don't meet the constraints, (indirectly) given in RFC 1123
section 2.1, on host names.

<URL:http://www.microsoft.com/technet/pr.../entserver/sag_DNS_pro_ChangeNameChecking.asp>

However, "host name" is not the same as "domain name", as RFC 1034
hints and as RFC 2181 more explicitly confirms, and the underscore
is perfectly legal in domain names.

Which (coming back to the original subject of discussion) invalidates
the proposed hypothesis that the mere presence of an underscore in the
domain name could be causing DNS lookup to fail somehow.
 
In
Jonathan de Boyne Pollard said:
Possibly because, as that article says, the server is checking
the domain names given in the update messages and rejecting those
that don't meet the constraints, (indirectly) given in RFC 1123
section 2.1, on host names.

<URL:http://www.microsoft.com/technet/prodtechnol/windowsserver2003/proddocs
/entserver/sag_DNS_pro_ChangeNameChecking.asp>

However, "host name" is not the same as "domain name", as RFC 1034
hints and as RFC 2181 more explicitly confirms, and the underscore
is perfectly legal in domain names.

Which (coming back to the original subject of discussion) invalidates
the proposed hypothesis that the mere presence of an underscore in the
domain name could be causing DNS lookup to fail somehow.
Click to expand...

I agree with you Jonathan and it all makes sense.

Maybe we should revisit the original post and ask which clients can't access
it and which type of clients can, are the different clients on the same
network, same SP level, IE and OS hotifxes, patches, updates, and if
possible, if the domain name was changed to remove the underscore, would
that make a difference? Are the clients ALL pointing to the internal DNS
server only (where this record is created) and not the ISP's (which would
only confuse the matter), etc.

Maybe a little more info on the config would help, such as an ipconfig /all
from a client that can resolve it and one from a client that cannot, is AD
involved, etc. Also, a ping test to the webserver's name and by IP from both
clients would be helpful to see.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory
 
AF> Maybe we should revisit the original post and ask which clients
AF> can't access it and which type of clients can, are the different
AF> clients on the same network, same SP level, IE and OS hotifxes,
AF> patches, updates, and if possible, if the domain name was changed
AF> to remove the underscore, would that make a difference?

Indeed. I've already asked for a description of what the observed behaviour
actually is - what the error messages actually say. For all we know, "can't
access the URL" and "it does not work from some machines" could be entirely
unrelated to DNS.
 
In
Jonathan de Boyne Pollard said:
Indeed. I've already asked for a description of what the observed
behaviour actually is - what the error messages actually say. For
all we know, "can't access the URL" and "it does not work from some
machines" could be entirely unrelated to DNS.
Click to expand...

I agree. Hopefully once we get a response we can help out better.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory
 
Back
Top