S2E3_IPSEC VPN - MM_WAIT_MSG4 - How to troubleshoot? (IPSEC VPN) 

How to troubleshoot MM_WAIT messages? What is the meaning of each MM_WAIT message? How to understand them?
This can be a really useful video for people working at service desk/IT desk, in security domain, Cisco TAC or any TAC that deals with firewalls or VPNs as a part of their job.
There are some other VPN related videos that you might be interested in. I am putting them all here so that you dont have to look around.
Understand how an IPSEC VPN comes up, what information is shared in each packet. After watching these videos you should have sufficient information to answer any question on the topic.
1. 1st Packet: • IPSEC 6 packet Exchang...
2. 2nd packet: • IPSEC 6 packet Exchang...
3. 3rd packet: • IPSEC 6 packet Exchang...
4. 4th packet: • IPSEC 6 packet Exchang...
5. 5th & 6th packet: • IPSEC 6 packet Exchang...
Extra one: How cookies are generated : • IPSEC 6 packet Exchang...
Then you would like to understand how to troubleshoot the problems:
1. MM_WAIT_MSG2 : • S2E1_IPSEC VPN - MM_WA...
2. MM_WAIT_MSG3: • S2E2_IPSEC VPN - MM_WA...
3. MM_WAIT_MSG4: • S2E3_IPSEC VPN - MM_WA...
4. MM_WAIT_MSG5 & MSG6: • S2E4_IPSEC VPN - MM_WA...
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What is Aggressive mode and how it is different than Main mode? How does it work?
• S3E1_IPSEC VPN_Aggress...
How to cofigure Cisco Anyconnect? Understand the concepts.
• Understanding & Config...
What is client Profile in Cisco Anyconnect and what is its importance?
• Cisco Anyconnect - Ove...
How to troubleshoot Cisco Anyconnect related Problems?
• Cisco Anyconnect Troub...