> For the complete documentation index, see [llms.txt](https://prosbcdocs.telcobridges.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://prosbcdocs.telcobridges.com/tmedia-documentation/platforms-and-hardware/internal-subnets.md). # Internal Subnets This article explains usage of the internal network subnets of TMG800, TMG3200 and TMG7800 products. These products **need to use private internal subnets** for communication between internal modules, and communication units and servers. **These subnets must not conflict with other subnets** assigned to the other IP interfaces of the units, including management (MGMT0), and VOIP IP interfaces. ### Procedure to change the internal subnets * [Change Internal Subnets of a TMG Unit](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/platforms/changing-the-internal-subnets/README.md) ### Summary table | | int0\* 172.31.1.1/255.255.255.252 Range: 172.31.1.1 - 172.31.1.3 | eth0 172.16.0.0/255.254.0.0 Range: 172.16.0.1 - 172.17.255.255 | eth1 172.18.0.0/255.254.0.0 Range: 172.18.0.1 - 172.19.255.255 | | ------------------ | ---------------------------------------------------------------- | -------------------------------------------------------------- | -------------------------------------------------------------- | | TMG800 Standalone | Required | | | | TMG3200 Standalone | Required | | | | TMG800 1+1 | Required | Required | Required | | TMG3200 1+1 | Required | Required | Required | | TMG7800 | | Required | Required | * Not all units support changing this subnet ### General information #### Intra-Unit private 'int0' subnet **Usage** This subnet is used for communication between Embedded host and Telecommunication board within the unit. **Products using this subnet** This subnet is used by all TMG800 and TMG3200 products. This subnet is not used by TMG7800 products. **Default IP / Netmask** The default IP / Netmask for this subnet is: **172.31.1.1 / 255.255.255.252** (range 172.31.1.1 - 172.31.1.3). **Support for changing this subnet** This subnet cannot be changed on most TMG800 and TMG3200 Units. To determine if your unit allows changing this subnet, [please use this procedure](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/platforms/changing-the-internal-subnets/README.md), and see if the subnet configuration web pages allow changing this subnet or not. #### Inter-Unit private 'eth0' and 'eth1' subnets **Usage** These subnets are used for reliable and redundant communication between Units of the system (between two TMG800 or TMG3200 in 1+1 mode, or between servers and Units of a TMG7800 system). **Products using these subnets** These subnets are used by TMG800 and TMG3200 units configured in 1+1 mode. They are not used in Standalone mode. These subnets are used by all TMG7800 systems. **Default IP / Netmask** The default IP / Netmask for 'eth0' subnet is: **172.16.0.0 / 255.254.0.0** (range 172.16.0.1 - 172.17.255.255) The default IP / Netmask for 'eth1' subnet is: **172.18.0.0 / 255.254.0.0** (range 172.18.0.1 - 172.19.255.255) Note that these subnets use a large netmask, allowing each shipped Unit to have a unique IP address on these subnets set in production. This is very convenient, because it allows to add a new 'off-the-shelf' TMG7800 Telecom Unit to an existing TMG7800 system without manually changing the IP address of eth0 and eth1 interfaces. It also allows inserting a new 'off-the-shelf' unit (or replacement unit) in a TMG800 or TMG3200 1+1 system without manually changing the IP addresses. **Support for changing these subnets** The eth0 and eth1 subnets can be changed on all products (TMG800, TMG3200 and TMG7800), using [this procedure](https://github.com/telcobridges-main/tmedia-wiki/tree/main/tmedia/platforms/changing-the-internal-subnets/README.md). --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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