We use FWSM inside our network to protect our server subnets. One of the server is using RMC that is based on Microsoft DCOM.
My understanding is the DCOM uses port tcp/135 for the beginning of the conversation. It than switches to a port in the 1024-65535 range. It just seams like a waste of a firewall to open all ports in that range.
My understanding is that the DCERPC inspection is suppose to work on this protocol. This inspection is turned on in the global policy map and set for default.
service-policy global_policy global
Is there anything special I need to get this going? Do I really need to open all tcp ports between 1024-65535?
Also ensure all communiction is in TCP and not UDP.
You can also use the 'established' command on the firewall instead of opening all ports falt out. However the established command is subject to some serious security riks (by virtue of bypassing the state checking).
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...