Sonicwall TZ500 VPN with Libreswan

Setting up IPSEC VPN between Sonicwall TZ500 and Libreswan (running on Rocky 8 linux)

DH Groups

• group1—768-bit Modular Exponential (MODP) algorithm.

• group2—1024-bit MODP algorithm.

• group5—1536-bit MODP algorithm.

• group14—2048-bit MODP group.

• group15—3072-bit MODP algorithm.

• group16—4096-bit MODP algorithm.

• group19—256-bit random Elliptic Curve Groups modulo a Prime (ECP groups) algorithm.

• group20—384-bit random ECP groups algorithm.

• group21—521-bit random ECP groups algorithm.

• group24—2048-bit MODP Group with 256-bit prime order subgroup.

Linux side

conn aus2sydo

  type=tunnel

  authby=secret

  auto=start

  pfs=no

  ike=aes256-sha1;dh5

  ikev2=insist

  esp=aes256-sha1

  lifetime=28800

  #salifetime=28800

  aggrmode=no

  left=%defaultroute

  leftid=<pub IP of linux server>

  leftsubnets={subnet of linux server}

  right=<pub IP of sonicwall>

  rightsubnet=<ip or subnet of sonicwall side>