# Troubleshoot DHCP and Static IPs on FileWave Debian Appliances

## What

FileWave provides Debian appliances for these components:

- FileWave Server
- Booster
- IVS

FileWave Debian appliances use DHCP by default. The same networking principles apply to other Debian installations, but the commands and examples here focus on FileWave appliances.

<p class="callout info">Give each appliance a stable address by configuring a static IP on the appliance or creating a DHCP reservation.</p>

## Why

Every customer network has its own addressing plan. Assign a stable address during initial setup so the Server, Booster, or IVS does not unexpectedly move when a DHCP lease changes.

## Information

The following articles offer details for configuring static addresses on FileWave Appliances:

- [FileWave Server Setup](https://kb.filewave.com/books/evaluation-guide/page/filewave-server-setup "FileWave Server Setup")
- [Networking - Assign static IP Address for a FileWave Booster Appliance](https://kb.filewave.com/books/filewave-general-info/page/networking-assign-static-ip-address-for-a-filewave-appliance "Networking - Assign static IP Address for a FileWave Booster Appliance")
- [IVS Control Commands](https://kb.filewave.com/books/network-imaging-ivs/page/ivs-control-commands "IVS Control Commands")

A DHCP reservation assigns the chosen IP to the appliance MAC address on the DHCP server instead of configuring the address locally.

### Troubleshooting

Example customer report to the FileWave Support Team:

#### Report

*"Despite having a DHCP reservation, the Booster was not assigned the expected IP address."*

#### Resolution

FileWave Technical Support found two DHCP servers offering addresses on the same subnet. Only one server contained the reservation for the expected IP.

### Avoid overlapping DHCP assignments

When more than one DHCP server serves a subnet:

- Give each DHCP server a unique address pool. **Do not let two servers offer the same addresses on one subnet.**
- Configure a reserved IP for an appliance MAC address on only one DHCP server for that subnet.
- Place the reservation on the server that owns the desired IP range.

<p class="callout warning">Overlapping address pools and relying on DHCP synchronisation is not recommended.</p>

Use these Debian commands to inspect interfaces, leases, and neighboring devices:

<table id="bkmrk-command-description-" style="border-collapse:collapse;width:100%;"><colgroup><col style="width:34.761905%;"></col><col style="width:65.119048%;"></col></colgroup><tbody><tr><td>Command</td><td>Description</td></tr><tr><td>```
ip a
```

  
</td><td>Show network interfaces, IP addresses, and MAC addresses.</td></tr><tr><td>```
ls /sys/class/net
```

  
</td><td>List network interface names.</td></tr><tr><td>  
```
dhclient <name of network interface>
```

  
</td><td>Refresh the DHCP lease for the named interface.</td></tr><tr><td>  
```
arp -a
```

  
</td><td>Display the network neighbor cache.</td></tr></tbody></table>

#### Examples:

The following `ip a` output shows two interfaces. In this example, `ens192` carries external traffic.

```
# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:1d:1c:75 brd ff:ff:ff:ff:ff:ff
    altname enp11s0
    inet 10.85.1.9/24 brd 10.85.1.255 scope global ens192
       valid_lft forever preferred_lft forever
```

<p class="callout info">'lo' is the [local loopback address](https://en.wikipedia.org/wiki/Loopback)</p>

<p class="callout info">Use the interface output to find the MAC address needed for a DHCP reservation.</p>

To list interface names without the address details:

```
# ls /sys/class/net
ens192	lo
```

If the appliance receives the wrong address, renew the DHCP lease for the active interface. Using `ens192` from the example:

```
# dhclient ens192
```

<p class="callout info">Run `dhclient` as root.</p>

`arp -a` can help identify address conflicts. This example shows the DHCP/DNS server and two devices in the appliance's neighbor cache.

```
# arp -a
Linksys38496.home (10.85.1.1) at d8:9f:80:4c:24:67 [ether] on ens192
FW1063.home (10.85.1.230) at 5c:96:cf:db:62:3b [ether] on ens192
ml1063.home (10.85.1.136) at ac:d0:74:68:23:6d [ether] on ens192
```

## Related Content

- [Networking - Assign static IP Address for a FileWave Appliance](https://kb.filewave.com/books/filewave-general-info/page/networking-assign-static-ip-address-for-a-filewave-appliance "Networking - Assign static IP Address for a FileWave Appliance")