Round Robin Problem help if poss please

T0GGLe · Feb 16, 2004

HI,

Setup is:-
Windows 2000 Active Directory mixed mode. Only a couple of NT boxes
and they are member servers only as they can't be domain
controllers....if i remember right :-)

2 domains-fqdn:-
domain1.internal.co.uk (2 dns servers here servicing this domain)
domain2.domain1.internal.co.uk (1 dns server here servicing this
domain)

Now we would like to use the round robin method within DNS to load
balance a few of servers in domain1...
So I enter in A-name (alias) records into DNS so that when clients
connect to this given network name their requests are sent to
different servers and hence we achieve load balancing.
HOWEVER! After a few days all but the first entry that we put in have
disapeared and therefore we're not load balancing at all - in fact we
havn't achieved anything except a few scratched heads and just the one
A-name record!

er...help? I think I'm obviously doing something wrong but can't for
the life of me find out what.
Any ideas?

If ya gonna email just remove the 1 from the email address but please
post response as well for benefit of all.

T0GGLe · Feb 17, 2004

Come on people you know you want to ;-)

Deji Akomolafe · Feb 18, 2004

I want to ....... but I don't really understand what you are trying to do.
Could you try explaining it better?

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
www.akomolafe.com
www.iyaburo.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon

Ace Fekay [MVP] · Feb 18, 2004

In

T0GGLe said:
HI,

Setup is:-
Windows 2000 Active Directory mixed mode. Only a couple of NT boxes
and they are member servers only as they can't be domain
controllers....if i remember right
2 domains-fqdn:-
domain1.internal.co.uk (2 dns servers here servicing this domain)
domain2.domain1.internal.co.uk (1 dns server here servicing this
domain)

Now we would like to use the round robin method within DNS to load
balance a few of servers in domain1...
So I enter in A-name (alias) records into DNS so that when clients
connect to this given network name their requests are sent to
different servers and hence we achieve load balancing.
HOWEVER! After a few days all but the first entry that we put in have
disapeared and therefore we're not load balancing at all - in fact we
havn't achieved anything except a few scratched heads and just the one
A-name record!

er...help? I think I'm obviously doing something wrong but can't for
the life of me find out what.
Any ideas?

If ya gonna email just remove the 1 from the email address but please
post response as well for benefit of all.

IF, that is IF I understand what you're trying to do... do not use CNAMES
(aliases) for this, but rather A (host) records.

IF you want to load balance between mutliple servers, create mulitple same
name host records with different IPs.

IF trying to do this for DFS, don't, use DFS replicas.

Note: do not use this method for AD DCs.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

T0GGLe · Feb 18, 2004

IF, that is IF I understand what you're trying to do... do not use CNAMES

(aliases) for this, but rather A (host) records.

IF you want to load balance between mutliple servers, create mulitple same
name host records with different IPs.

IF trying to do this for DFS, don't, use DFS replicas.

Note: do not use this method for AD DCs.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

Hi folks, sorry if my explanation isn't very good. I'll try again.

Looks like Ace has got it - I am just trying to load balance requests
to a particular group of servers using the "round robin" technique.
This is when you have multiple entries for the same name in dns (eg
server1) but a different IP
address as per below:-
server 1 - 192.168.0.1
server 1 - 192.168.0.2
server 1 - 192.168.0.3

What happens is that dns is supposed to use the first address when
first queried on that name, then the second on the next query and so
on and so on. Therefore you are load balancing. It's called round
robin and that's what i meant when i said i'm trying to use round
robin, a techinque described by microsoft. Hope this helps Dèjì
Akómöláfé 'n' all

Also here's a note from Microsoft that explains it also:-

NOTE: The Microsoft DNS Server supports round robin, which is
a technique used as a form of load balancing between servers
(to get more information about this feature, refer to RFC
1794). This feature will make DNS send both IP addresses when
a query is received for myserver.mydomain.com. The client (or
Resolver) will always use the first one. The next time DNS
receives a query for this name the order of the list of IP
addresses is changed in a round robin fashion (the address
that was first in the previous list will be last in the new
list). Round Robin of Cname records is not supported because
there should be only one canonical name for any one alias.

Ok Ace i obviously got my description wrong - I meant 'A' records and
thought that i was talking about aliases so thanks for pointing out my
error.
Yes, we've been putting in multiple 'A' records for the same name but
with diferent IP addresses however after a few days all the entries
disappear except for the first one.
This is what has me stumped and what i require help with please.

We are not using cnames and this is not for dfs or any other MS
service/application.
TIA

Ace Fekay [MVP] · Feb 19, 2004

In

T0GGLe said:
Hi folks, sorry if my explanation isn't very good. I'll try again.

Looks like Ace has got it - I am just trying to load balance requests
to a particular group of servers using the "round robin" technique.
This is when you have multiple entries for the same name in dns (eg
server1) but a different IP
address as per below:-
server 1 - 192.168.0.1
server 1 - 192.168.0.2
server 1 - 192.168.0.3

What happens is that dns is supposed to use the first address when
first queried on that name, then the second on the next query and so
on and so on. Therefore you are load balancing. It's called round
robin and that's what i meant when i said i'm trying to use round
robin, a techinque described by microsoft. Hope this helps Dèjì
Akómöláfé 'n' all
Also here's a note from Microsoft that explains it also:-

Ok Ace i obviously got my description wrong - I meant 'A' records and
thought that i was talking about aliases so thanks for pointing out my
error.
Yes, we've been putting in multiple 'A' records for the same name but
with diferent IP addresses however after a few days all the entries
disappear except for the first one.
This is what has me stumped and what i require help with please.

We are not using cnames and this is not for dfs or any other MS
service/application.
TIA

If it's disappearing, then I'm going to assume that the address is for a
domain controller. If not, on the servers that you are using this for,
provided they are not DCs, I would uncheck the "register this connection" in
it's IP properties, advanced, DNS tab. Seems that dynamic registration is
killing it.

Let me know if that helps.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

T0GGLe · Feb 19, 2004

If it's disappearing, then I'm going to assume that the address is for a
domain controller. If not, on the servers that you are using this for,
provided they are not DCs, I would uncheck the "register this connection" in
it's IP properties, advanced, DNS tab. Seems that dynamic registration is
killing it.

Let me know if that helps.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

Ah ok Ace well that makes a lot of sense thanks very much we'll give that a go.

An no, it's not a DC that we are doing this for.

I'll let you know!

Deji Akomolafe · Feb 19, 2004

Seems like Ace has cleared up some parts of your issue. Let me clear up
another one, even though you didn't specifically ask about this:

What happens is that dns is supposed to use the first address when
first queried on that name, then the second on the next query and so
on and so on.

This is incorrect. As far as Windows DNS is concerned, the order of serving
up the addresses is NOT sequential. It is absolutely random and, sometimes,
even statically. There is no guarantee that a requesting client will NOT
always get the same record. MS DNS is a crude round-robin-er or load
balancer.

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
www.akomolafe.com
www.iyaburo.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon

Ace Fekay [MVP] · Feb 19, 2004

In

Deji Akomolafe said:
Seems like Ace has cleared up some parts of your issue. Let me clear
up another one, even though you didn't specifically ask about this:

This is incorrect. As far as Windows DNS is concerned, the order of
serving up the addresses is NOT sequential. It is absolutely random
and, sometimes, even statically. There is no guarantee that a
requesting client will NOT always get the same record. MS DNS is a
crude round-robin-er or load balancer.

Dèjì Akómöláfé, MCSE MCSA MCP+I

I was going to mention that! Forgot about it gettin involved with the other
issues!
Thanks Deji!

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

Deji Akomolafe · Feb 20, 2004

np, Ace

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
www.akomolafe.com
www.iyaburo.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon
"Ace Fekay [MVP]"

T0GGLe · Feb 20, 2004

Deji Akomolafe said:
np, Ace

--
Sincerely,

Dèjì Akómöláfé, MCSE MCSA MCP+I
www.akomolafe.com
www.iyaburo.com
Do you now realize that Today is the Tomorrow you were worried about
Yesterday? -anon

Right thanks for the extra info. Just one thing though the note that I
included was from an official MS document that i found but cannot find
now. However, it said the same as per the article below :-

http://www.microsoft.com/technet/tr...roddocs/datacenter/sag_DNS_imp_RoundRobin.asp

Now while i am WELL AWARE :0) that what MS says and how their products
actually work can be two completely different things, you are
basically saying that DNS round robin just DOES NOT necessarily work
properly at all?
ie the list of A records does not get rotated sequentially? I take it
you've tried this before have you guys? Otherwise I'd be interested to
know where you get the information as I'm reequired to provide that
information myself to my boss(s).
TIA
Togs.

Ace Fekay [MVP] · Feb 20, 2004

In

T0GGLe said:
Right thanks for the extra info. Just one thing though the note that I
included was from an official MS document that i found but cannot find
now. However, it said the same as per the article below :-

http://www.microsoft.com/technet/tr...roddocs/datacenter/sag_DNS_imp_RoundRobin.asp

Now while i am WELL AWARE :0) that what MS says and how their products
actually work can be two completely different things, you are
basically saying that DNS round robin just DOES NOT necessarily work
properly at all?
ie the list of A records does not get rotated sequentially? I take it
you've tried this before have you guys? Otherwise I'd be interested to
know where you get the information as I'm reequired to provide that
information myself to my boss(s).
TIA
Togs.

Test it. You'll see that you get random results. Use a few clients and you
can see what happens!
:-)

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

T0GGLe · Feb 23, 2004

Test it. You'll see that you get random results. Use a few clients and you
can see what happens!

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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

Cheers I'll give it a go soon. Just trying to wrestle with damn
Epolicy orchestrater at the moment, Mcafee's "solution" to rolling out
and updating your antivirus

Ace Fekay [MVP] · Feb 23, 2004

In

T0GGLe said:
Cheers I'll give it a go soon. Just trying to wrestle with damn
Epolicy orchestrater at the moment, Mcafee's "solution" to rolling out
and updating your antivirus

Hmm...haven't used that one. I've used Norton and it works great to push out
updates.

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.
This posting is provided "AS IS" with no warranties.

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