2 files changed, 70 insertions, 4 deletions
diff --git a/docs/_include/interface-common.txt b/docs/_include/interface-common.txt
index 4c6ebbe8..5a997482 100644
--- a/docs/_include/interface-common.txt
+++ b/docs/_include/interface-common.txt
@@ -22,10 +22,6 @@
   :var0: {{ var0 }}
   :var1: {{ var1 }}
 
-.. cmdinclude:: /_include/interface-adjust-mss.txt
-  :var0: {{ var0 }}
-  :var1: {{ var1 }}
-
 .. cmdinclude:: /_include/interface-ip.txt
   :var0: {{ var0 }}
   :var1: {{ var1 }}
diff --git a/docs/configuration/interfaces/pppoe.rst b/docs/configuration/interfaces/pppoe.rst
index 41f22ed6..ae6a8cba 100644
--- a/docs/configuration/interfaces/pppoe.rst
+++ b/docs/configuration/interfaces/pppoe.rst
@@ -177,6 +177,41 @@ PPPoE options
    PPPoE connection must be established over a physical interface. Interfaces
    can be regular Ethernet interfaces, VIFs or bonding interfaces/VIFs.
 
+.. cfgcmd:: set interfaces pppoe <interface> ip adjust-mss <mss>
+
+  As Internet wide PMTU discovery rarely works, we sometimes need to clamp our
+  TCP MSS value to a specific value. This is a field in the TCP options part of
+  a SYN packet. By setting the MSS value, you are telling the remote side
+  unequivocally 'do not try to send me packets bigger than this value'.
+
+  .. note:: This command was introduced in VyOS 1.4 - it was previously called:
+    ``set firewall options interface <name> adjust-mss <value>``
+
+  .. hint:: MSS value = MTU - 20 (IP header) - 20 (TCP header), resulting in
+    1452 bytes on a 1492 byte MTU.
+
+.. cfgcmd:: set interfaces pppoe <interface> ip disable-forwarding
+
+  Configure interface-specific Host/Router behaviour. If set, the interface will
+  switch to host mode and IPv6 forwarding will be disabled on this interface.
+
+.. cfgcmd:: set interfaces pppoe <interface> ip source-validation <strict | loose | disable>
+
+  Enable policy for source validation by reversed path, as specified in
+  :rfc:`3704`. Current recommended practice in :rfc:`3704` is to enable strict
+  mode to prevent IP spoofing from DDos attacks. If using asymmetric routing
+  or other complicated routing, then loose mode is recommended.
+
+  - strict: Each incoming packet is tested against the FIB and if the interface
+    is not the best reverse path the packet check will fail. By default failed
+    packets are discarded.
+
+  - loose: Each incoming packet's source address is also tested against the FIB
+    and if the source address is not reachable via any interface the packet
+    check will fail.
+
+  - disable: No source validation
+
 IPv6
 ----
 
@@ -189,6 +224,41 @@ IPv6
   :var0: pppoe
   :var1: pppoe0
 
+.. cfgcmd:: set interfaces pppoe <interface> ipv6 adjust-mss <mss>
+
+  As Internet wide PMTU discovery rarely works, we sometimes need to clamp our
+  TCP MSS value to a specific value. This is a field in the TCP options part of
+  a SYN packet. By setting the MSS value, you are telling the remote side
+  unequivocally 'do not try to send me packets bigger than this value'.
+
+  .. note:: This command was introduced in VyOS 1.4 - it was previously called:
+    ``set firewall options interface <name> adjust-mss <value>``
+
+  .. hint:: MSS value = MTU - 20 (IP header) - 20 (TCP header), resulting in
+    1452 bytes on a 1492 byte MTU.
+
+.. cfgcmd:: set interfaces pppoe <interface> ipv6 disable-forwarding
+
+  Configure interface-specific Host/Router behaviour. If set, the interface will
+  switch to host mode and IPv6 forwarding will be disabled on this interface.
+
+.. cfgcmd:: set interfaces pppoe <interface> ipv6 source-validation <strict | loose | disable>
+
+  Enable policy for source validation by reversed path, as specified in
+  :rfc:`3704`. Current recommended practice in :rfc:`3704` is to enable strict
+  mode to prevent IP spoofing from DDos attacks. If using asymmetric routing
+  or other complicated routing, then loose mode is recommended.
+
+  - strict: Each incoming packet is tested against the FIB and if the interface
+    is not the best reverse path the packet check will fail. By default failed
+    packets are discarded.
+
+  - loose: Each incoming packet's source address is also tested against the FIB
+    and if the source address is not reachable via any interface the packet
+    check will fail.
+
+  - disable: No source validation
+
 *********
 Operation
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