3 ms·

Network I am on atm, IPv6 give me both green, IPv4 MTU fails ... It means my IPv6 vpn is better than IPv4 delivered by some wannabe corpo network masters.

• pilif 9y ago
  the firewall is probably blocking ICMP. For a long time, it was considered best-practice to blanket-block ICMP and for a long time you could mostly get away with it. But over time some really useful stuff has been added to ICMPv4 (early congestion notification for example) and IPv6 mostly won't work at all without ICMP. I would argue that it's time for firewall administrators to reconsider this decision. The time where ICMP packets could do harm are long past (remember the ping-of-death on Windows 98?) and I would argue that the time when a network could work at peak efficiency (or at all) without ICMP are also mostly past.
  • joeseeder 9y ago
    Totally agree, ICMP is needed. When it's not blocked, you can debug and have healthy network, instead of a frankensteins monster.
  • oasisbob 9y ago
    > For a long time, it was considered best-practice to blanket-block ICMP I agree with your point, but think this needs some clarification about who considered it a best practice - among enterprise firewall admins and financial-industry compliance audits, perhaps. Large scale network operators have seen the problems associated with entirely blocking ICMP for at least a decade. (v4 has blackhole problems too) A lot of the hatred for ICMP came from simple things like easy endpoint discoverability. nmap blew that argument out of the water pretty quick.