RPC over HTTP / Outlook Anywhere

[Irish]

Hi Guys,

I'm having trouble with Outlook Anywhere, which uses RPC over HTTP.
As far as I know the problem does not lie with my laptop or its setup as it used to work perfectly fine on my home connection (Orange Broadband) now that I have moved to Uni and are connecting to Virgin Media Broadband the connection seems to constantly fail (Outlook repeatedly asks for the password - seems to suggest it cannot connect to the server), my questions are:

1. Is Virgin Media actively blocking / filtering 'encapsulated' commands, i.e. RPC over HTTP?
2. If 1 is not the case then does anyone know problems / limitations with a Belkin F5D7230-4 6000 Router Cable Modem? (The firewall is disabled.)

Any help appreciated,

James

[Uncle Peter]

No problems with RPC/HTTP here.

Is the advertised address for your service resolving ok and if so, what happens when you try to telnet to it on port 80 or 443 from a command prompt?

Are the ISA servers or firewall where your Exchange server is hosted blocking any ranges?

[Andrewcrawford23]

Originally Posted by Irish

Hi Guys,

I'm having trouble with Outlook Anywhere, which uses RPC over HTTP.
As far as I know the problem does not lie with my laptop or its setup as it used to work perfectly fine on my home connection (Orange Broadband) now that I have moved to Uni and are connecting to Virgin Media Broadband the connection seems to constantly fail (Outlook repeatedly asks for the password - seems to suggest it cannot connect to the server), my questions are:

1. Is Virgin Media actively blocking / filtering 'encapsulated' commands, i.e. RPC over HTTP?
2. If 1 is not the case then does anyone know problems / limitations with a Belkin F5D7230-4 6000 Router Cable Modem? (The firewall is disabled.)

Any help appreciated,

James

Sounds like your port forwarding isnt set up right, sicne you can access it internally but not external that wher ei start first. port forwarding isnt needed on internel welll usual unless it not default ports

[Ignitionnet]

Think you misread the OP, it's nothing to do with port forwarding, if it were we'd be needing port forwarding to browse websites. Port forwarding is only an 'issue' with incoming connections, and there's no reference to 'internal' or otherwise beyond that it works fine over Orange Broadband but apparently not over Virgin Media. Outlook Anywhere is no different from browsing an HTTP(s) site beyond what's carried inside the HTTP(s) payload. Unless OP is running an Exchange server on his Orange DSL there's no inbound / outbound and OP is not hosting the Exchange on his DSL, he just mentions it working ok via Orange.

Port forwarding is not needed internally whether on default or non-default ports. If internal to the server then you aren't going to be going through a firewall / NAT gateway to be port translated but routed which is why port forwarding is a non-issue internally.

Remember that port forwarding is there to overcome dynamic NAT - port forwarding makes the NAT static so that it's a 1:1 relationship between port and machine - come in on port x you will always go to machine y, otherwise you would best case go to a DMZ machine, or most likely the packet would just be dropped as the firewall has no entry in its' state table for the connection.

James - are you using a VPN to access Outlook Anywhere or is it a normal HTTPS / SSL session?

I'm asking as Virgin Media doesn't seem to like VPNs too much - they seem to have issues with fragmented packets.

Also what MTU do you have set on your routers and your PCs?

James,

Welcome to to CF

I've had this issue before....do you have a firewall enabled? If so - disabled it (for testing) try connected to see what happens - chances are it'll connect and work which will make it a firewall issue.

Don't forget to re-enable the firewall...

Edit: Mods - this is not a VM issue - needs moving to Networking!

[Ignitionnet]

Originally Posted by Irish

2. If 1 is not the case then does anyone know problems / limitations with a Belkin F5D7230-4 6000 Router Cable Modem? (The firewall is disabled.)

I meant software firewall....

[Andrewcrawford23]

Originally Posted by Broadbandings

Think you misread the OP, it's nothing to do with port forwarding, if it were we'd be needing port forwarding to browse websites. Port forwarding is only an 'issue' with incoming connections, and there's no reference to 'internal' or otherwise beyond that it works fine over Orange Broadband but apparently not over Virgin Media. Outlook Anywhere is no different from browsing an HTTP(s) site beyond what's carried inside the HTTP(s) payload. Unless OP is running an Exchange server on his Orange DSL there's no inbound / outbound and OP is not hosting the Exchange on his DSL, he just mentions it working ok via Orange.

Port forwarding is not needed internally whether on default or non-default ports. If internal to the server then you aren't going to be going through a firewall / NAT gateway to be port translated but routed which is why port forwarding is a non-issue internally.

Remember that port forwarding is there to overcome dynamic NAT - port forwarding makes the NAT static so that it's a 1:1 relationship between port and machine - come in on port x you will always go to machine y, otherwise you would best case go to a DMZ machine, or most likely the packet would just be dropped as the firewall has no entry in its' state table for the connection.

James - are you using a VPN to access Outlook Anywhere or is it a normal HTTPS / SSL session?

I'm asking as Virgin Media doesn't seem to like VPNs too much - they seem to have issues with fragmented packets.

Also what MTU do you have set on your routers and your PCs?

I think you shoudl reread it, they said home connection wher eteh whatever it is there trying to access is working. Then they say extrenal virginmedia at uni so explain that one to me please as if that does not qualify as internel external gods know what doe sin your book

Are you unable to read wha ti wrote? i said port forwarding isnt normally needed internal.....

You must only havea problem with VPN with virign as i have 3 vpn connection workign perfectly fine nothing dropped

[Stuart]

Outlook Anywhere does not use VPN. It uses RPC commands sent over port 80 (the HTTP port). This is why assuming web browsing works, port forwarding is not the issue, whether internal or external.

[Andrewcrawford23]

Originally Posted by Stuart C

Outlook Anywhere does not use VPN. It uses RPC commands sent over port 80 (the HTTP port). This is why assuming web browsing works, port forwarding is not the issue, whether internal or external.

i never said it was vpn......

they have already said there behind a router.....

so if port 80 is not forward to the correct machine it would cause problems.....

but i do not have much informatrion on outlook anywhere so can not give specific help only general help to look at but i will just accept what your and others are saying sinc ei do nto know hte program, i also was guessing outlook anywhere was exchange sevrer by a post before mines

[Stuart]

Outlook anywhere isn't a program (as such). It is the web interface to Exchange server..

[Ignitionnet]

Originally Posted by LSainsbury

I meant software firewall....

Software firewall won't block web browsing

---------- Post added at 22:40 ---------- Previous post was at 22:31 ----------

Originally Posted by Andrewcrawford23

I think you shoudl reread it, they said home connection wher eteh whatever it is there trying to access is working. Then they say extrenal virginmedia at uni so explain that one to me please as if that does not qualify as internel external gods know what doe sin your book

Are you unable to read wha ti wrote? i said port forwarding isnt normally needed internal.....

You must only havea problem with VPN with virign as i have 3 vpn connection workign perfectly fine nothing dropped

Port forwarding doesn't happen internally full stop, if you have something running on a non-standard port you just point your client to it. Think where ports are forwarded, how and why. Your comment about needing port forwarding if running services on non-standard points internally didn't make sense, if on the same network as the server you won't go through any port or network translation just switched straight to the server.

OP didn't use the word 'external' at any point during their post.

I wanted to check on the VPN component as I needed to eliminate issues with MTUs on VM, I use Outlook Anywhere with no issues from home. Some VPNs struggle with packets being fragmented and need their MTUs dropped so that they don't break MTU.

What might be of value James if you don't have a solution would be if you could get a hold of Wireshark http://www.wireshark.org/ - get it monitoring your network card or wireless depending what you use and then record the packets while you attempt to access the Exchange Anywhere.

I am suspecting the router of doing something silly though, that or OP has an IP address in a former BOGON range and the ISA server or firewall is still configured to block it.

[Andrewcrawford23]

Originally Posted by Stuart C

Outlook anywhere isn't a program (as such). It is the web interface to Exchange server..

so i did get it right although i never knew the web interface was called outlook anywhere, the ports do need to be forwarded then

---------- Post added at 22:47 ---------- Previous post was at 22:44 ----------

Originally Posted by Broadbandings

Software firewall won't block web browsing

---------- Post added at 22:40 ---------- Previous post was at 22:31 ----------



Port forwarding doesn't happen internally full stop, if you have something running on a non-standard port you just point your client to it. Think where ports are forwarded, how and why. Your comment about needing port forwarding if running services on non-standard points internally didn't make sense, if on the same network as the server you won't go through any port or network translation just switched straight to the server.

OP didn't use the word 'external' at any point during their post.

I wanted to check on the VPN component as I needed to eliminate issues with MTUs on VM, I use Outlook Anywhere with no issues from home. Some VPNs struggle with packets being fragmented and need their MTUs dropped so that they don't break MTU.

What might be of value James if you don't have a solution would be if you could get a hold of Wireshark http://www.wireshark.org/ - get it monitoring your network card or wireless depending what you use and then record the packets while you attempt to access the Exchange Anywhere.

I am suspecting the router of doing something silly though, that or OP has an IP address in a former BOGON range and the ISA server or firewall is still configured to block it.

there isa rare occassion where port forwarding is required even internally if it none standard ports are used

oh btw software firewall do block web browsing think you should go have anotehr look at them

they said home so that means internal, then said uni that means external unless oyu are tryting to tell me there uni is home then if that was the case they would not havea problem would they? because itnernalyl it is working.......

[Uncle Peter]

@James it may also be worth checking the login credentials in your mapi profile, inparticular if you're passing the domain part in the username field (in the form: domain\user). This is often required depending on how your techies have configured the front-end or CAS server. You never know, things may have changed on the server side without you knowing... unless you know for sure of course

[Ignitionnet]

Originally Posted by Andrewcrawford23

so i did get it right although i never knew the web interface was called outlook anywhere, the ports do need to be forwarded then

---------- Post added at 22:47 ---------- Previous post was at 22:44 ----------



there isa rare occassion where port forwarding is required even internally if it none standard ports are used

oh btw software firewall do block web browsing think you should go have anotehr look at them

they said home so that means internal, then said uni that means external unless oyu are tryting to tell me there uni is home then if that was the case they would not havea problem would they? because itnernalyl it is working.......

Strewth. It's not an Exchange server running at this home Andrew, it's elsewhere. It works fine from his Orange broadband ergo it's not an issue with port forwarding at the server side. People rarely run Exchange, which Outlook Anywhere is a front end for, at home.

People who run Exchange servers tend to not mess up things like 'port forwarding' and chances are it's not using port forwarding but static NAT and a virtual IP translating everything going to a public IP to the private IP address of the server in question.

If his software firewall were blocking web browsing he'd have had a rather troubled time posting this thread wouldn't he? I think we're probably safe to ignore that one, and yes I know what software firewalls do, it's why I don't use one of the horrid things

I do hope when you troubleshoot at work you read more carefully. The Exchange server is somewhere in Internet land, it works fine from his Orange DSL, it doesn't from his Virgin Media cable. It's not that he is hosting it locally, sane people don't set up a personal Exchange server on their broadband.

Anyway onto the point.

Irish, either get a packet trace or maybe get the techies who operate the server to see if you are actually reaching it using the Virgin Media cable connection. You mentioned getting a password prompt but you didn't mention at what point, are you seeing the initial screen requesting the logon? Are you giving the full domain and username info if you do according to the prompting? If you're going over ordinary http have you tried going over https?