Understanding the ICMP Protocol with Wireshark in Real Time
Jan 21, 2022 · Understanding ICMP Protocol with Wireshark in Real Time • Questions: • What is the MTU size of the ICMP packet at the Network Layer? • What is the MTU size of the ICMP packet at …
ARP and ICMP Which layers?? - Cisco Learning Network
ICMP is OSI layer 3 (Network layer) and ARP is OSI layer 2 (Date Link layer) . If you use the TCP/IP Model or Internet Protocol Suite, then ICMP is layer 2 (Internet layer) and ARP is layer 1 (Link …
Firewall rules for ICMP (TCP/UDP port 7) - Cisco Learning Network
Sep 25, 2017 · What exactly is the firewall rule? ICMP has no ports and is neither TCP nor UDP. ICMP is IP protocol 1 (see RFC792), TCP is IP protocol 6 (described in RFC793) and UDP is IP protocol …
How Traceroute Works Explained in Detail - Cisco Learning Network
Oct 20, 2025 · How Traceroute Works Explained in Detail • Traceroute, like the ping command can be used to isolate problems in our network. • The ping command is a bit limited sometimes. • Example: • …
Should I disable ICMP request? - Cisco Learning Network
I'd like to know if the ICMP protocol should be disable in IPv4 to stop incoming requests? I've heard that pings is a tool that an attacker can use to get information about your network. But also, I've read that …
Enable icmp from ASA to IPSec VPN clients - Cisco Learning Network
to enable ping to the outside interface, we should add a line to the access-list splittunnel and allow icmp access to outside interface: icmp permit 10.0.0.0 255.255.255.0 outside access-list splittunnel …
ICMP echo reply Port? - Cisco Learning Network
ICMP echo reply Port? Hi everyone, There is a lot of debate on the Internet regarding ICMP being layer 3 or layer 4, as supposedly it uses port 7 for the latter as an echo reply (I did see someone comment …
ICMP with different port numbers - Cisco Learning Network
As ICMP works directly over IP layer, it does not carry any TCP/UDP ports, however, we can still issue ping and traceroute commands using different port numbers. I can understand that the port number …
ICMP - network unreachable vs host unreachable
The ICMP Destination Unreachable message is sent by a router in response to a packet which it cannot forward because the destination (or next hop) is unreachable or a service is unavailable. Examples …
IP SLA icmp-echo question - Cisco Learning Network
IP SLA monitor is a separate process that has its values, and based on those values IP SLA monitor sends and measure the ICMP probes, which could be different than the default ICMP timer on the …