By default, 65520 bytes are advertised, and zero disables DHCP and
NDP options.
Fixes: ec2b58ea4dc4 ("conf, dhcp, ndp: Fix message about default MTU, make NDP
consistent")
Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>
---
passt.1 | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/passt.1 b/passt.1
index 6136fa5..4c90634 100644
--- a/passt.1
+++ b/passt.1
@@ -135,8 +135,10 @@ background (if configured to do so).
.TP
.BR \-m ", " \-\-mtu " " \fImtu
-Assign \fImtu\fR via DHCP (option 26) and NDP (option type 5).
-By default, no MTU options will be sent.
+Assign \fImtu\fR via DHCP (option 26) and NDP (option type 5). A zero value
+disables assignment.
+By default, the advertised MTU is 65520 bytes, that is, the maximum 802.3 MTU
+minus the length of a 802.3 header, rounded to 32 bits (IPv4 words).
.TP
.BR \-a ", " \-\-address " " \fIaddr
--
2.39.2