topic Re: Inside interface keeps beeing intermittent in Network Security

Inside interface keeps beeing intermittent

SegBorda — Thu, 20 Aug 2020 14:33:26 GMT

Dears, good morning.

I am passing throw some problems in our border Cisco ASA 5525-X appliance.

Operatinal System Version: 9.12(4)
ASDM: 7.13(1)

The problems are:

1) Our inside interface keeps beeing intermittent. Inside interface keeps going down momentarily in a period of approximately five minutes. It happens several times in a day. The intersting part is is that all new connections and established continue passing throw the firewall. Howerver, I loose connectivity with icmp packets, asdm management access on tcp/443 and SNMP; and

2) The real-time log viewer is not showing all the sources and destinations packets. It keeps showing some source and NAT address.

This problem is impacting our network and I am here to ask for some help, please.

Best regards.

Re: Inside interface keeps beeing intermittent

Rob Ingram — Thu, 20 Aug 2020 14:52:59 GMT

Hi,
Check the switch the inside interface is connected to, run "show logging" and determine whether the interface has any associated error messages.

HTH

Re: Inside interface keeps beeing intermittent

SegBorda — Thu, 20 Aug 2020 16:43:41 GMT

Dear Rob,

I´m sorry but can you make myself clear?

I did not understand what you wish to tell me with "Check the switch the inside interface is connected to"...

Thanks a lot

Re: Inside interface keeps beeing intermittent

Rob Ingram — Thu, 20 Aug 2020 16:48:53 GMT

The ASA is plugged into a physical switch. I suggested you login to that switch and check the logs to see if there are any errors associated to the interface the ASA is connected to.

Re: Inside interface keeps beeing intermittent

SegBorda — Thu, 20 Aug 2020 17:05:52 GMT

Rob,

On my premisses the appliance is connected to a double interface server (netfilter).

That is Netfilter (Oracle Linux) <-> Cisco ASA <-> Internet.

Would you suggest any command?

Re: Inside interface keeps beeing intermittent

SegBorda — Thu, 20 Aug 2020 17:31:40 GMT

I got this output:

[root@iptables firewall]# netstat -in
Tabela de Interfaces do Kernel
Iface MTU    RX-OK              RX-ERR    RX-DRP    RX-OVR    TX-OK              TX-ERR     TX-DRP TX-OVR Flg
em1 1500    63108047747 15180      58492      0               75624234823 0               0                 0     BMRU
em2 1500    70552618319 561291    633482    0               34108804279 0               0                 0     BMRU
em3 1500 0 0 0 0 0 0 0 0 BMU
em4 1500 0 0 0 0 0 0 0 0 BMU
lo 65536 1032 0 0 0 1032 0 0 0 LRU
[root@iptables firewall]#

I think I dont have error.

Re: Inside interface keeps beeing intermittent

SegBorda — Mon, 24 Aug 2020 17:10:07 GMT

Dears,

I am still having problem.

Can anyone help me, please ?