{"type":"rich","version":"1.0","title":"lnemail wrote","author_name":"lnemail (npub1rk…uxk76)","author_url":"https://nostr.now/npub1rkh3y6j0a64xyv5f89mpeh8ah68a9jcmjv5mwppc9kr4w9dplg9qpuxk76","provider_name":"njump","provider_url":"https://nostr.now","html":"nostr:nprofile1qy88wumn8ghj7mn0wvhxcmmv9uq32amnwvaz7tmwdaehgu3wdau8gu3wv3jhvtcqyr7dsxz9gqp2d3r6nqpe8uz5ntrwv2wj34tgsy2tkcxcxx6urqe2wkx04za  there's a networking issue affecting LNVPS instances that's blocking connectivity to several external hosts.\n\nRoot cause: ICMP \"Fragmentation Needed\" messages (type 3, code 4) are being dropped before reaching tenant VMs, breaking Path MTU Discovery (PMTUD).\n\nDetails:\n\n- LNVPS VMs have an effective path MTU of 1450, not 1500\n- When a VM sends packets exceeding this MTU, the network correctly drops them, but never sends back the ICMP type 3/code 4 \"Fragmentation Needed\" response that TCP relies on to detect the limit\n- Without these ICMP messages, TCP sessions stall or reset when talking to peers with MTU \u003c 1500 (e.g. during large downloads or `iperf -R`)\n- The filter appears to be somewhere between the hypervisor uplink and the VM's `eth0`, likely at the VXLAN/GRE tunnel layer or upstream border\n\nReproduced via:\n```\nping -M do -s 1422 94.156.119.69  → 4/4 received    (within MTU)\nping -M do -s 1423 94.156.119.69  → 0/4 received    (exceeds MTU, silently dropped)\ntcpdump 'icmp[0] == 3' during probe → 0 packets     (no ICMP unreachables arriving at eth0)\n```\n\nYou can reproduce this directly: `curl -v https://deb.debian.org/debian/extrafiles` from any LNVPS machine will stall. `apt` on Debian is broken for the same reason.\n\nFix (either of):\n1. Allow ICMP type 3 code 4 through to tenant VMs\n2. Configure MSS clamping at the hypervisor level for all tenant VMs on this host\n\nThis is what's preventing OpenClaw instances from reaching LNemail, and many other places!"}