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New Member

Vanishing routes from ASA Config


Have An ASA with the following statements:

ASA Version 7.2(4)9

route Inside Y.Y.Y.Y 1

route Inside Y.Y.Y.Y 1

route Outside X.X.X.X 1

Made a Change and only add The rule:

route Outside X.X.X.X 1

About 30m after the change The folowing messages started appeared in Syslog:

%ASA-4-419002: Duplicate TCP SYN from Outside:Z.Z.Z.Z/Z to Outside: with different initial sequence number

And Outside Users cant go to and

It was a loop possibly in the outside.

after Checking the config:

the Inside entries have disappeared from the Configuration:

route Inside Y.Y.Y.Y 1

route Inside Y.Y.Y.Y 1

Inserting the missing statements again in config solved the problem, no more disappearing routes after that:

route Inside Y.Y.Y.Y 1

route Inside Y.Y.Y.Y 1

Has anyone seen this behavior?

Seems very strange that route statements simply had disappeared from config.

Thanks in advance


New Member

Re: Vanishing routes from ASA Config


the solution is simple. It seems, you are having the same or an overlapping subnet on the inside and outside interface. The dissappeared routes are hostroutes. If you are adding an route for an overlapping subnet, the devices thinks, this will be for the host routes too, an kick them for the config. After that, you can add them again. But, you shouldn't have overlapping subnets at different interfaces. It's dirty. Wondering why it's working....