# First session

> Write a minimal config, start ansage and check that the neighbor has your prefixes.

### Write a config

```toml title="/etc/ansage/ansage.toml"
asn = 64500
router_id = "203.0.113.1"
announce = ["192.0.2.0/24", "2001:db8:1::/48"]

[[neighbor]]
address = "10.0.0.1"
asn = 64501
```

`ansage check -c /etc/ansage/ansage.toml` validates it without starting anything. Every
setting is in the [config reference](/docs/reference/config.md).

### Start ansage

Under systemd (see [Install](/docs/getting-started/install.md)):

```sh
systemctl start ansage
```

Or in the foreground:

```sh
ansage --config /etc/ansage/ansage.toml [--log-format text|json]
```

### Check the session

```sh
ansage show summary
```

```txt
ansage 0.4.0, AS 64500, router ID 203.0.113.1, up 4.0s
RIB: 2 IPv4 and 2 IPv6 prefixes, 3 attribute sets
Announcing: 192.0.2.0/24 2001:db8:1::/48

ID  NEIGHBOR       AS     STATE        FOR   RCVD v4/v6  SENT v4/v6  DESCRIPTION
1   10.0.0.1:179   64501  Established  4.0s  0/0         1/1         -
```

`Established` and `SENT 1/1`: the neighbor has both prefixes. `ansage show peer 10.0.0.1`
shows the details, and why a session is not up. All client commands take `--json`, and
`-s SOCKET` (or `-c CONFIG` to find its socket).

### Check on the router

**FRR:**

```sh
vtysh -c 'show bgp ipv4 unicast 192.0.2.0/24'
```

**BIRD:**

```sh
birdc show route 192.0.2.0/24 all
```

The router needs a neighbor for ansage too, see [Router configs](/docs/guides/router-config.md).

## Who connects

By default ansage connects to its neighbors and accepts nothing. To accept connections from
configured neighbors as well, set `listen`; a neighbor with `passive = true` is never
connected to, ansage waits for it:

```toml
listen = ["0.0.0.0:179", "[::]:179"]

[[neighbor]]
address = "10.0.0.1"
asn = 64501
passive = true
```

> **Note:** Port 179 needs CAP_NET_BIND_SERVICE; the systemd unit grants it.

## Next steps

- One session carries IPv4 and IPv6: if it runs over IPv4, set `next_hop_ipv6`, see [Next hops](/docs/guides/next-hops.md).
- Several servers with the same prefix: [Run an anycast service](/docs/guides/anycast.md).
- Withdraw when the service fails: [Health checks](/docs/guides/health-checks.md).