summaryrefslogtreecommitdiff
path: root/fw/src
diff options
context:
space:
mode:
Diffstat (limited to 'fw/src')
-rw-r--r--fw/src/fw.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/fw/src/fw.c b/fw/src/fw.c
index 4dc6d79..70bcc5c 100644
--- a/fw/src/fw.c
+++ b/fw/src/fw.c
@@ -306,9 +306,13 @@ wireup(Wire *w)
if(fprint(w->cfd, "bind pkt") < 0)
sysfatal("%s: bind pkt: %r", w->net);
/*
- * pktmedium claims 4096 with no link header; a card is 1514 with
- * 14. Left alone the protected stack emits packets the card
- * refuses, and only remote peers capping the MSS hide it.
+ * pktmedium claims 4096 with no link header, where a card is 1514
+ * with 14, so a stack behind one of these thinks it may send 4096
+ * bytes. In card mode devether then refuses the frame outright;
+ * between two stacks the packet only has further to go before an
+ * ether interface refuses it. Either way 1500 is what the traffic
+ * will meet in the end, so say so here. Left alone, the only
+ * thing hiding it is remote peers capping the MSS.
*/
if(fprint(w->cfd, "mtu 1500") < 0)
fprint(2, "fw: %s: cannot set mtu: %r\n", w->net);