We have an Ironport WSA 370 at a client which has a strange issue. Webpages fail to load if using the domain, but work if you try direct by IP. After a flushdns on the ironport, accessing pages via domain works fine - for a period. The client is having to flushdns at the start of the day, then repeat 2-3 times throughout the day.
I've tried using the DNS server on the Domain Controller, Google DNS, and the ISP dns. If you test via the CLI on the WSA, you can ping domain names without any issues which show dns resolution is working.
I tried upgrading to the latest version, and the issue persists.
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...
[toc:faq]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 and UDP are I...