docs nat: fix nat-ha ascii art

  See: https://docs.fd.io/vpp/19.08/nat_ha_doc.html

Type: docs

Change-Id: I43ecf1dfb6976ebafee04d820f0e1b07393a0b93
Signed-off-by: Paul Vinciguerra <[email protected]>

diff --git a/src/plugins/nat/nat_ha_doc.md b/src/plugins/nat/nat_ha_doc.md
index 2d50423..f0ea209 100644 (file)
--- a/src/plugins/nat/nat_ha_doc.md
+++ b/src/plugins/nat/nat_ha_doc.md
@@ -13,6 +13,7 @@ Session synchronization traffic is distributed through an IPv4 UDP connection. T
 
 The two NAT nodes have a dedicated link (interface GE0/0/3 on both) to synchronize NAT sessions using NAT HA protocol.
 
+```
         +-----------------------+
         |    outside network    |
         +-----------------------+
@@ -36,6 +37,7 @@ The two NAT nodes have a dedicated link (interface GE0/0/3 on both) to synchroni
         +-----------------------+
         |    inside network     |
         +-----------------------+
+```
 
 ### Active node configuration