"RPC Server is unavailable" when atempting to remote into ISA 2004 server
Posted on 2008-10-07
We deployed a new ISA 2004 Standard Server with SP3 into our organization and it was functioning fine for about a month now. Today remote users reported that they are unable to VPN into the network (PPTP), I pointed some of the remote users to the old ISA server temporarily.
After rebooting the server everything seemed fine for about an hour, later I tried to remote into the server (mstsc) and I receive the following message:
"The system cannot log you onn due to the following error:
The RPC Server is unavailable.
Please try again or consult your system administrator"
I rebooted the server and tried again.. still no luck. I noticed that Routing and Remote Access were disabled on the ISA. I did run repair on the network connections, then started the Routing and Remote Access.
I had also started both services (which were disabled):
Remote Procedure Call (RPC)
Remote Procedure Call (RPC) Locator
Our internal network is 10.0.0.0- 10.0.0.255
I noticed that ISA is throwing a lot of error messages stating that:
"ISA Server detected routes through the network adapter outside LAN that do not correlate with the network to which this network adapter belong. Then later in the message it lists 10.0.1.0-10.255.255.254"
I had a similar issue on the old ISA server and when we corrected the LAN to 10.0.0.0 - 10.0.0.255 we started getting other error messages.
After the ISA server with the issue was restarted I noticed that users are now able to VPN in to our network, but we are still unable to remote into it.
ISA BPA Tool lists the following:
Policy rule blocks FTP Uploads
Policy rule blocks FTP Uploads
Receive Side SCaling (RSS) is enabled by the OS
TCP Accelerator (TCPA) is enabled by the OS
Configuration error - same as the error I listed above in the question
The lower and Upper limits of the source port range for an access rule are equal (Stream/Download/IM block on 1214)
The RADIUS server can not be accessed
VPN Connection failure signaled x times (users were not able to VPN in earlier)
There are no cvertificates in the local computer store (we will not be publiching any SSL certs on this server)
Outlook WebAccesspublishing rule listends on HTTP (this rule will be disabled once HTTPS and SSL are ready)
Path maximum Transmission Unit (MTU) discovery is disabled
All of the Firewall System Policy rules are enabled with the exception for the ones below:
4 Allow Remote Logging to trusted servers using NETBIOS
13 Allow VPN site-to-site traffic to ISA server
14 Allow VPN site-to-site traffic from ISA server
16 Allow remote SQL logging from ISA server to selected servers
18 Allow HTTP/HTTPS requests from ISA server to selected servers
19 Allow access from trusted computers to the firewall client installation share on ISA server
20 Allow remote performance monitoring of ISA server from trusted servers
24 Allow SecurID
25 Allow remote monitoring from ISA server to trusted servers, using MOM Agent
26 Allow HTTP traffic from IS server to all network (for CRL downloads)
29 Allow HTTP from ISA server to selected computers for Conetnet download jobs
Any help is greatly appreciated.