Eugenio Tampieri's blog

GS108Ev3 configuration file format reverse engineering

Disclaimer: The fields marked with ? have not been verified.

How I did it

Easy. I just changed the options on the web UI, downloaded the configuration file, see what changed. Rinse and repeat.

Types

• Field separator: 0x00 0x01 0x00 plus one byte that is the length of the field
• Strings: C-like, null terminated.

File description

• 0x00-0x05: 0x46 0x4D 0x76 0x32 0x02 0x32 Header
• 0x06-0x07: Checksum (?)
• 0x08-0x18: QOS
  • 0x08-0x0B: Field separator, length: 0x0D
  • 0x0C-0x0F: "qos" string
  • 0x10: bool flag: 0x01 -> 802.1p QoS, 0x00 port based QoS
  • 0x11-0x18: port priority. 0x11 -> port 1, 0x18 -> port 8. Entire range to 0x00 if [0x10] is 0x01 Priorities:
    • 0x07: High
    • 0x05: Medium
    • 0x03: Normal
    • 0x01: Low
• 0x19-0x61: Rate limiting
  • 0x19-0x1C: Field separator, length: 0x45
  • 0x1D-0x21: "rate" string, NULL terminated
  • For each port: Ingress rate and egress rate. The rate is in LE, 4 bytes, 1Mbps = 1024 kbps; 1000 bps = 1kbps
• 0x62-0x8F: Storm protection
  • 0x62-0x65: Field separator, length: 0x2A
  • 0x6C-0x6F: 0xFF 0x00 0x00 0x00 (?)
  • For each port: Storm control rate. The rate is in LE, 4 bytes, 1Mbps = 1024 kbps; 1000 bps = 1kbps
• 0x90-0xA4: Port mirroring
  • 0x90-0x93: Field separator, length: 0x11
  • 0x94-0x9A: "mirror" string
  • 0x9B-0xA2: 0x01 if we want to mirror this port, 0x00 otherwise
  • 0xA3: Destination port, 0 based (port 1 is 0x00, port 8 is 0x07)
  • 0xA4: 0x00 (?)
• 0xA5-0x239: VLAN configuration
  • 0xA5-0xA8: Field separator, length: 0x89
  • 0xA9-0xAD: "vlan" string
  • 0xAE-0xAF: 0x04 0x00 (VLAN mode?)
  • 0xB0-0xB1: Number of VLANs
  • For each VLAN (0xB2-0xDC:
    • 2 bytes: VLAN ID (LE)
    • 1 byte: Untagged ports (bit 7 is port 8, ..., bit 0 is port 1. This way, 0x82 means that we're selecting ports 8 and 2)
    • 1 byte: Tagged ports (same as above)
• 0x132-0x14A: PVID
  • 0x132-0x135: Field separator, length: 0x15
  • 0x136-0x13A: "pvid" string
  • 0x13B-0x14A: for each port, 2 bytes (LE) for the PVID
• 0x14B-0x155: Multicast settings
  • 0x14B-0x14E: Field separator, length: 0x07
  • 0x14F-0x154: "mcast" string
  • 0x155: Block Unknown Multicast Address -> 0x01, else 0x00
• 0x156-0x167: IGMP snooping
  • 0x156-0x159: Field separator, length: 0x0E
  • 0x15A-0x163: "igmpsnoop" string
  • 0x164: Enable IGMP snooping (0x01)
  • 0x165-0x166: VLAN id (LE)
  • 0x167: Validate IGMPv3 IP Header (0x01)
• 0x168-0x182
  • 0x168-0x16B: Field separator, length: 0x17
  • 0x16C-0x175: "ethconfig" string
  • 0x176: Enable (0x01) static IP
  • 0x177-0x17A: IPv4 address (or 0x00 0x00 0x00 0x00 for DHCP)
  • 0x17B-0x17E: IPv4 netmask (or 0x00 0x00 0x00 0x00 for DHCP)
  • 0x17F-0x182: IPv4 gateway (or 0x00 0x00 0x00 0x00 for DHCP)
• 0x183-0x1A4: Password (?)
• 0x1A5-0x1ED: Device name
  • 0x1A5-0x1A8: Field separator, length: 0x45
  • 0x1A9-0x1AD: "name" string
  • 0x1AE-0x1C2: name (string)
• 0x1EE-0x1FF: Registration
  • 0x1EE-0x1F1: Field separator, length: 0x0E
  • 0xF2-0xFE: "registration" string
  • 0xFF: Boolean flag (?)
• 0x200-0x20F: Loop detect
  • 0x200-0x203: Field separator, length: 0x0C
  • 0x204-0x20E: "loopdetect" string
  • 0x20F: Boolean flag
• 0x210-0x228: Misc
  • 0x210-0x213: Field separator, length: 0x15
  • 0x214-0x218: "misc" string
  • 0x219-0x228: 0x00 0x01 0x00 0x01 0x00 0x01 0x00 0x01 0x00 0x01 0x00 0x01 0x00 0x01 0x00 0x01
• 0x229-0x239: Toggle Plus utility
  • 0x229-0x22C: Field separator, length: 0x0D
  • 0x22D-0x238: "plusutility" string
  • 0x239: 0x01 to disable the ProSafe utility, 0x00 to enable it