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# maximumTransmissionUnit

An integer value that indicates the maximum transmission unit (MTU) associated with this attachment.

```
var maximumTransmissionUnit: Int { get set }
```

## Discussion

The client side of the associated datagram socket must be properly configured with the appropriate values for `SO_SNDBUF`, and `SO_RCVBUF`. Set these using the `setsockopt(_:_:_:_:_:)` system call. The system expects the value of `SO_RCVBUF` to be at least double the value of `SO_SNDBUF`, and for optimal performance, the recommended value of `SO_RCVBUF` is four times the value of `SO_SNDBUF`.

The default MTU is 1500. The maximum MTU allowed is 65535, and the minimum MTU allowed is 1500. An invalid MTU value results in an invalid virtual machine configuration.

---

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