Cisco ASA FW (capture command) is not detecting existing UDP messages

[Joerg.Teske]

I have a question related to the interface of a Cisco router.

I have two cases of UDP flows arriving at a Cisco port (I can see them e.g. by connecting the ethernet cable to Wireshark on a windows PC).

The first case behaves as expected (with a capture command I see the UDP packages from 10.61.7.1 to 10.61.7.2

In the second case (source is not in the local LAN) I do not see the UDP packackes on the Cisco port (with a capture command I do NOT see any the UDP packages from 10.61.7.1 to  10.61.50.2

As written above, with Wireshark you can see that the UDP packages are visible on this interface. 

Except to find a way to change the source address (has not intended impact) I do not see how I can change the definition of the interface:

interface GigabitEthernet1/1
  description interface
  nameif ifName
  security-level 10
  ip address 10.61.50.3 255.255.255.0
!

[MHM Cisco World]

Let check first case' how traffic between two host in same subnet hit FW interface?

What FW mode you run

MHM

[Joerg.Teske]

Sorry, for sure:
Cisco Firewall ASA 5508 K9 (asa984-43-lfbff-k8.SPA )

Best regards

Jörg

[MHM Cisco World]

friend I ask about the mode of operation 
router or transparent 
the traffic between two host in same subnet not need to pass via GW (in this case it FW)
MHM

[Joerg.Teske]

For test the two elements are directly connected (Ethernet cable - no routing):

[cid:image004.png@01DA3F10.77093650]

[Joerg.Teske]

Updated figures:

[MHM Cisco World]

check below notes 
why ASA see traffic forward to other host not it interface ?

[Joerg.Teske · Accepted solution]

Thank you for the notes.

Finally I found the problem.

Due to a very big arp timeout (14400) and first connection of the equipment I did not see that the MAC was still not known.

Over night the problem was disappeared. Sorry for this fault (both cases are now working as expected).

[MHM Cisco World]

dont worry friend 
Glad issue is solved 
have a nice day 
MHM