---
title: "dhcpd: icmp_echorequest 192.0.2.1: No buffer space available"
slug: "aa-01444"
description: "This log message means that the socket send buffer has overflowed."
tags: ["isc dhcp"]
updated: 2018-10-30T19:47:50Z
published: 2018-10-30T19:47:51Z
canonical: "kb.isc.org/aa-01444"
---

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# Why is my server logging: "dhcpd: icmp_echorequest 192.0.2.1: No buffer space available"?

```
dhcpd: icmp_echorequest 192.0.2.1: No buffer space available
```

The kernel has returned an error ENOBUFS to **dhcpd** in response to the ICMP (ping) message that **dhcpd** sends with ping-check enabled.

This means that the socket send buffer has overflowed; **dhcpd** is sending messages faster than the kernel is able to transmit them to the network. This could indicate that there is another problem on the server itself, or it may simply be that you need to increase the buffer size.

We suggest as your next steps:

1. Disable your firewall/iptables. If this solves the problem, your firewall or packet filtering is creating delays on outbound packet transmissions.
2. Review and adjust Linux kernel settings `wmem_default` and `wmem_max`.

You will need to restart dhcpd after adjusting Linux kernel settings wmem_default and wmem_maxThe **dhcpd** socket send buffer is allocated when the socket is created; this means that you will need to restart **dhcpd** for the new settings to take effect.