BGPSee

BGPSee is a multi-threaded BGP client for the CLI. It's goal it to allow you to quickly and easily view the BGP paths that a peer or peers are advertising. Previously you would have had to either spin-up a virtual routers, or use a Linux routing daemon (FRR, Zebra, etc) to view this information.

Version

Current version is 0.0.3

Major changes from 0.0.2 to 0.0.3:

• Now supports JSON as an output format.
• Now requires jansson library to support JSON output.

Seee the CHANGELOG for further information.

Versions < 0.1.0 are considered beta version of bgpsee. There may be rough edges, and the CLI interface is subject to major changes between versions. By default BGPSee will compile with debug symbols and a number of other compile-time sanitisation flags. If bgpsee crashes, I would ask you to please raise an issue and copy/paste the crash output into the issue.

Usage

Usage: bgpsee [options...] <peer> [<peer> ...]
-s, --source <ip>	IP to source BGP connection from
-a, --asn <asn>		Local ASN of bgpsee. If not provided 65000 will be used.
-r, --rid <ip>		Local router ID of bgpsee. If not provided 1.1.1.1 will be used.
-l, --logging <level>	Logging output level, 0: BGP messages only, 1: Errors, 2: Warnings, 3: Info (default), 4: Debug 
-f, --format <fmt>	Format of the output, <fmt> may be 'json' or 'kv'. Defaults to 'json'
-h, --help		Print this help message

<peer> formats: <ip>,<asn> or <ip>,<asn>,<name>

Example

Here's an example of bgpsee peering with an external router. You only see BGP messages recieved from the peer, not the messages sent by bgpsee iteslef.

./bgpsee -f json --asn 65001 fw1.i.foletta.xyz,65011,"External Router"

{
  "recv_time": 1701025221,
  "peer_name": "External Router",
  "id": 0,
  "type": "OPEN",
  "length": 69,
  "message": {
    "version": 4,
    "asn": 65011,
    "hold_time": 180,
    "router_id": "10.50.254.1",
    "optional_parameter_length": 40
  }
}
{
  "recv_time": 1701025222,
  "peer_name": "External Router",
  "id": 1,
  "type": "KEEPALIVE",
  "length": 19,
  "message": {}
}
{
  "recv_time": 1701025844,
  "peer_name": "External Router",
  "id": 2336,
  "type": "UPDATE",
  "length": 97,
  "message": {
    "withdrawn_route_length": 0,
    "withdrawn_routes": [],
    "path_attribute_length": 70,
    "path_attributes": {
      "ORIGIN": "IGP",
      "AS_PATH": {
        "n_as_segments": 2,
        "n_total_as": 1,
        "path_segments": [
          {
            "type": "AS_SEQUENCE",
            "n_as": 5,
            "asns": [
              45270,
              4764,
              3356,
              1299,
              56595
            ]
          },
          {
            "type": "AS_SET",
            "n_as": 1,
            "asns": [
              23456
            ]
          }
        ]
      },
      "NEXT_HOP": "10.50.254.1",
      "AGGREGATOR": {
        "aggregator_asn": 56595,
        "aggregator_ip": "192.124.193.146"
      }
    },
    "nlri": [
      "5.172.183.0/24"
    ]
  }
}

We see a connection to an external router, with the peer router sending an OPEN and an immediate KEEPALIVE signalling it accepts the OPEN message we sent. After 5 seconds the peer starts sending UPDATEs from all of the paths it has. This router has a full BGP table, and shown is one of the paths that contains most of the path attributes, including AGGREGATOR and an AS_PATH with AS segments.

Building

As of version 0.0.3, bgpsee now requires libjansson. You'll need to install the development libraries before building, for example

# Debian based distros
sudo apt install libjansson-dev

# Red Hat based distros
sudo yum install jansson-devel

To build simply download/clone and build using make:

git clone --recurse-submodules https://github.com/gregfoletta/bgpsee.git
cd bgpsee
make

This builds a bgpsee executable in the root directory. There is no make install.

Roadmap

Top 3 items to add in future releases:

• Expansion on the BGP Path Attribute handling, with a priority on:
  • COMMUNITY
  • EXTENDED COMMUNITIES
  • MP_REACH_NLRI