workmac, ssh: tune multiplexing timeouts

Adjust multiplexing settings to avoid being stuck for too long when the
control master has issues or the target host e.g. rebooted.
Relevant e.g. when used for reboot recovery check pings.

home/workmac.nix

@@ -35,9 +35,11 @@ in
     # defaults in bottom match block "*"
     # TODO: common config for desktop as well
     # multiplexer, e.g. to avoid rate limiting on jumphost usage
-    serverAliveInterval = 60;
+    serverAliveInterval = 10;
+    serverAliveCountMax = 2; # 2 strikes and you're out
     controlMaster = "auto";
-    controlPersist = "4h";
+    # not too long, due to the frequent keepalives
+    controlPersist = "1h";
     # ssh host config
     matchBlocks = {
 
@@ -45,7 +47,6 @@ in
       "*" = {
         extraOptions = {
           IdentityAgent = "\"~/Library/Group Containers/2BUA8C4S2C.com.1password/t/agent.sock\"";
-          #ControlPath = "/tmp/ssh_mux_%h_%p_%r";
         };
       };
 
@@ -107,7 +108,7 @@ in
         "0"
         "-D"
         "1080"
-        "-oServerAliveInterval=60"
+        "-oServerAliveInterval=30"
         "-oControlMaster=no"
         "-N"
         "vpn-whq.services.fcio.net"