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Configuring Network Overrides

Applies to:
  • CrashPlan PROe

Overview

Administrators can control how quickly source devices are allowed to send backup data to their destinations. Independent bandwidth throttle settings exist for both LAN and WAN.

The default LAN and WAN rules work well in most cases; however, you can specify your own LAN and WAN rules if your network topology requires additional granularity. This article describes how to use network overrides to specify your own LAN and WAN rules.

Considerations

The information in this article applies to enterprise server version 3.5.3 and later.

How it works

The source device determines whether to apply the LAN or WAN network rules by looking at the IP address of the backup destination. By default, the LAN network bandwidth settings apply when the backup destination's IP address matches one of the following IP addresses or ranges:

  • Private: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16
  • Link Local: 169.254.0.0/16
  • Loopback: 127.x.x.x

If the destination IP does not match the list above, the WAN rules apply.

Network overrides

The master server provides a way to override the default LAN/WAN rules, which allows administrators to account for varying network topologies and use cases. When the Network overrides field under Settings > Device > Network > Network overrides is populated, the device performs a new calculation based on the local device's IP address. Network override entries must be in IPv4 CIDR notation, e.g. 192.168.1.0/24.

If the source IP address matches the IP address or range specified under Network overrides, then the source device changes the destination's designation from LAN to WAN, or vice versa.

The following flowchart explains the process more clearly:

Network Overrides Flowchart

Examples

In the examples below, the IP address of the destination is assumed to be part of a private network range if the source device has been assigned an IP address from a private network. If the source device IP address is public, then the destination's IP address is also assumed to be public.

Case study 1

  • Industry: Sales
  • Users: 100
  • Home office user backs up over the VPN modem, and VPN bandwidth is very limited
  • Business goal: Limit the amount of bandwidth that the device is allowed to use when backing up over the VPN modem

Desired outcome: If user's VPN modem assigns an IP address in the range 192.168.0.0/24, use WAN throttling. Otherwise, use default WAN and LAN throttling.

Create the following network override entry in Settings > Device > Network > Network overrides:

WAN LAN
192.168.0.0/24

Devices with VPN addresses are always in the 192.168.0.0/24 network range. In the default case, a device connecting via the VPN is considered LAN, since the device's IP address is in one of the private IP network ranges (192.168.0.0/16) and is backing up to a destination on the corporate network with an IP address of 10.10.10.5.

With the WAN network override in place, however, the WAN network override forces the device to apply the WAN throttling rules.

Case study 2

A company assigns VPN users one of the following ranges:

  • 10.1.0.0/16
  • 10.2.0.0/16
  • 10.3.0.0/16
  • 203.0.113.0/24

In this case, VPN users may be assigned to either a private IP range (10.x.x.x/16), or a public IP range (203.0.113.0/24).

Desired outcome: WAN throttling applies to all devices in any of the VPN network ranges listed above.

Create the following network override entries in Settings > Device > Network > Network overrides:

WAN LAN
10.1.0.0/16
10.2.0.0/16
10.3.0.0/16
203.0.113.0/24

For devices with a VPN address:

  • If connecting to LAN, WAN Network overrides match VPN address. WAN throttling applies.
  • If connecting to WAN, LAN Network overrides fail to match (there are no entries). Stay with WAN throttling.

For devices without a VPN address:

  • If connecting to LAN, WAN network overrides do not match. LAN throttling applies.
  • If connecting to WAN, LAN overrides fail to match (there are no entries). Stay with WAN throttling.

Case study 3

Devices connecting through the WAN are assigned IP addresses in the range 203.0.113.0/24. The corporate WAN has high bandwidth, however, and LAN throttling should be used.

Create the following network override entries in Settings > Device > Network > Network overrides:

WAN LAN
203.0.113.0/24

For devices with a 203.x address, LAN network overrides match. LAN throttling applies.

For devices without a 203.x address:

  • If connecting to LAN, WAN network overrides fail to match. LAN throttling applies.
  • If connecting to WAN, LAN network overrides fail to match. Stay with WAN throttling.

Case study 4

If a device is in the range 10.0.0.0/8, apply WAN throttling settings. Otherwise, assign LAN settings to all other devices in all other ranges.

Create the following network override entries in Settings > Device > Network > Network overrides:

WAN LAN
10.0.0.0/8 0.0.0.0/5
8.0.0.0/7
11.0.0.0/8
12.0.0.0/6
16.0.0.0/4
32.0.0.0/3
64.0.0.0/2
128.0.0.0/1

For devices with a 10.x address, WAN overrides match. WAN throttling applies.

For devices without a 10.x address:

  • If connecting to LAN, WAN overrides fail to match. LAN throttling applies.
  • If connecting to WAN, LAN overrides match. LAN throttling applies.

Note

The LAN list above is the entire possible IP range minus 10.0.0.0/8.

The list was created with cidrmerge tool: http://cidrmerge.sourceforge.net/

(cidrmerge was called with 0.0.0.0/0, with an exclude whitelist of 10.0.0.0/8)

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External resources

Wikipedia: Classless Inter-Domain Routing (CIDR)