---
name: "fragtest"
section: "8"
platform: "linux"
package: "fragroute"
version: "1.2-7.1"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/fragtest"
---

# fragtest(8)

test IP fragment reassembly behaviour

## NAME

fragtest - test IP fragment reassembly behaviour

## SYNOPSIS

**fragtest** *TESTS ... host*

## DESCRIPTION

**fragtest** probes the remote *host* to determine its TCP/IP stack behaviour.

The  *TESTS* may include any of the following (or may be specified as **all** to perform them all):

- **ping**

  Send an ICMP echo request to the host.

- **ip-opt**

  Send ICMP echo requests with different IP options, to see which IP options are supported.

- **frag**

  Send an ICMP echo request as 8-byte fragments.

- **frag-new**

  Send an ICMP echo request as 8-byte fragments with an overlapping 16-byte fragment, favoring newer data in reassembly.

- **frag-old**

  Send an ICMP echo request as 8-byte fragments with an overlapping 16-byte fragment, favoring older data in reassembly.

- **frag-timeout**

  Send an ICMP echo request as 8-byte fragments, omitting the last fragment, and wait for an ICMP time-exceeded-in-reassembly reply.

## SEE ALSO

[**fragroute**(8)](/fragroute/8.md)

## AUTHOR

Dug Song \<dugsong@monkey.org\>

## BUGS

Firewalls or other filtering network devices may block IP fragments, packets with IP options, ICMP echo traffic, etc.