ipsec - What's the difference between IKE and ISAKMP
However, a common framework is required for agreeing to the format of SA attributes and for negotiating, modifying and deleting SAs. ISAKMP serves as this common framework. ISAKMP can be implemented over any transport protocol. All implementations must include send and receive capability for ISAKMP using UDP on port 500. Configuring IPsec Virtual Private Networks Jul 02, 2020 vpn - What might prevent IKE handshake success in building ISAKMP traffic on UDP port 500; ISAKMP (used for NAT-Tunnelling) traffic on UDP port 4500; ESP traffic (IP Protocol 50) AH traffic (IP Protocol 51) It seems a lot of people out there don't realise the important difference between IP protocols and TCP/UDP ports. The following packet captures focussed on the above types of traffic. zywall 110 failing PCI Compliance port 500(isakmp) — Zyxel
With ISAKMP/IPSec, the IPSec policy agent may only send responses from queries back to UDP port 500. In this case, it is best for PortQry to use UDP port 500 as the source port for the query. If the IPSec policy agent is running on the computer where PortQry runs, UDP port 500 is unavailable because the policy agent is using the port.
[SOLVED] Disable Port 500 (isakmp) on ZyWALL 110 Nov 09, 2018 DMVPN - ISAKMP UDP 512/BIFF instead of UDP 500 ??? : Cisco
Xbox One (LIVE) ports: 3074 TCP/UDP, 53 TCP/UDP, 80 TCP, 88 UDP, 500 UDP, 3544 UDP, 4500 UDP isakmp_sub_print in tcpdump 3.6 through 3.7.1 allows remote attackers to cause a denial of service (CPU consumption) via a certain malformed ISAKMP packet to UDP port 500, which causes tcpdump to enter an infinite loop. References: [CVE-2003-0108]
Configuring IPsec Virtual Private Networks