(module-services)=
# Network Services Configuration Module

The initial version of the Network Services configuration module implements [DNS clients and servers](services-dns-platform), with syslog, NTP, and SNMP planned for future releases.

```eval_rst
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```

(services-dns-platform)=
## DNS Support

_netlab_ can configure DNS clients or servers on these platforms:

| Operating system      | IPv4 DNS<br>client | IPv6 DNS<br>client | Transport<br>VRF | DNS server |
| --------------------- | :-: | :-: | :-: | :-: |
| Arista EOS            | ✅  | ✅  | ✅  |  ❌  |
| Cisco IOS/IOS XE[^18v]| ✅  | ✅  | ✅  |  ❌  |
| FRR (containers)      | ✅  | ✅  | ❌  |  ❌  |
| Linux (containers)    | ✅  | ✅  | ❌  |  ❌  |
| dnsmasq               | ✅  | ✅  | ❌  |  ✅  |

[^18v]: Includes Cisco CSR 1000v, Cisco Catalyst 8000v, Cisco IOSv, Cisco IOSv L2 image, Cisco IOS-on-Linux (IOL), and IOL Layer-2 image.

(services-dns-parameters)=
## DNS Parameters

You can configure the DNS client with the global/node **services.dns** dictionary:

* **services.dns.domain** (string): The lab domain (default: `netlab.local`)
* **services.dns.server** (node name or list of node names): Specifies the DNS server(s) node name. The node name(s) are resolved to IPv4/IPv6 addresses, which are then used to configure the lab devices.
* **services.dns.ipv4** and **services.dns.ipv6** (address or list of addresses): Hard-coded IPv4/IPv6 DNS server addresses.
* **services.dns.transport_vrf**: the VRF used to reach the DNS server.

The DNS server is configured with the **services.server.dns** parameter, which can be a boolean value or a dictionary with these parameters:

* **forwarder.ipv4** and **forwarder.ipv6** (address or list of addresses): upstream DNS servers used for name resolution of domains other than **services.dns.domain**.