From ed957ddf337f1a5794fad8510051e9ae35d8a6bb Mon Sep 17 00:00:00 2001
From: tengel <tengel@xyzzy.ee>
Date: Wed, 20 Mar 2024 11:55:04 -0500
Subject: [PATCH] adding TCP Kill

---
 TCP-Kill.md | 30 ++++++++++++++++++++++++++++++
 _Sidebar.md |  1 +
 2 files changed, 31 insertions(+)
 create mode 100644 TCP-Kill.md

diff --git a/TCP-Kill.md b/TCP-Kill.md
new file mode 100644
index 0000000..21381a6
--- /dev/null
+++ b/TCP-Kill.md
@@ -0,0 +1,30 @@
+## Killing a stalled TCP connection
+
+Requires: kernel >= 4.9 with `CONFIG_INET_DIAG_DESTROY`
+
+Scenario: subprocess `rclone` has encountered trouble and started to stall out, running at a severely decreased rate of speed
+
+Task: pause rclone, kill the in-progress TCP connection, resume rclone which will trigger it to (re)create a new, working TCP connection (app dependent)
+
+### Steps
+
+Find the process and it's TCP stalled connection:
+
+```
+$ ps axo pid,comm | grep [r]clone
+  6874 rclone
+
+$ ss -ntp | grep [r]clone | awk '{print $5, $6}'
+74.120.9.121:443 users:(("rclone",pid=6874,fd=9))
+```
+
+Pause the process, kill the connection (as root), resume the process:
+
+```
+$ kill -STOP 6874
+
+$ sudo ss -K dst 74.120.8.14 dport 443
+
+$ kill -CONT 6874
+```
+
diff --git a/_Sidebar.md b/_Sidebar.md
index bed0751..7d5d226 100644
--- a/_Sidebar.md
+++ b/_Sidebar.md
@@ -54,6 +54,7 @@
 - [[Smem Datamash]]
 - [[Split Disk]]
 - [[systemd PID1]]
+- [[TCP Kill]]
 - [[Thunderbird LDAP AD]]
 - [[uBlock Filters]]
 - [[udev Hide Partitions]]