Network
MTU / MSS Path Calculator
Calculate how much each tunnel or encapsulation layer consumes from your interface MTU, the effective TCP MSS, and the DF ping probe size. For SRE, SD-WAN, and k8s CNI engineers.
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Quick start
Call this tool from your code in three languages.
cURL
curl -X POST 'https://api.elysiatools.com/en/api/tools/mtu-and-mss-path-calculator' \
-H 'Content-Type: application/json' \
-d '{"mtu":1500,"encapsulationStack":"pppoe","innerIpVersion":"ipv4","tcpHeader":20,"customOverhead":0}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
HTTP
POST https://api.elysiatools.com/en/api/tools/mtu-and-mss-path-calculatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| mtu | number | Yes | — |
| encapsulationStack | text | No | Comma-separated list of layers, outermost first. Valid values: vlan, qinq, pppoe, gre, gre_checksum, vxlan, geneve, wireguard4, wireguard6, ipsec_transport, ipsec_tunnel. |
| innerIpVersion | select | No | — |
| tcpHeader | number | No | — |
| customOverhead | number | No |
MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
mcp.json
{
"mcpServers": {
"elysiatools-mtu-and-mss-path-calculator": {
"name": "mtu-and-mss-path-calculator",
"description": "Calculate how much each tunnel or encapsulation layer consumes from your interface MTU, the effective TCP MSS, and the DF ping probe size. For SRE, SD-WAN, and k8s CNI engineers.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=mtu-and-mss-path-calculator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
tools/list
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
tools/call
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "mtu-and-mss-path-calculator",
"arguments": {
"mtu": 1500,
"encapsulationStack": "pppoe",
"innerIpVersion": "ipv4",
"tcpHeader": 20,
"customOverhead": 0
}
}
}Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).
Questions or issues? Contact [email protected]