# unbound "sendto failed: No buffer space available"



## goshanecr (Jan 30, 2018)

Good day!

I have a FreeBSD 11.1 amd64 box as router for about 300 users.
On that server works unbound (from system, not ports) as resolver for network. And in /var/log/messages I such messages:

```
Jan 30 11:29:10 MAIN-GATE unbound: [59552:2] notice: sendto failed: No buffer space available
Jan 30 11:29:10 MAIN-GATE unbound: [59552:2] notice: remote address is 192.168.0.57 port 52656
```

That's my unbound settings:

```
server:
        verbosity:      1

        port:           53
        interface:      10.0.0.1
        interface-automatic:    no
        outgoing-interface:     103.45.12.4
        do-ip4:         yes
        do-ip6:         no
        do-udp:         yes
        do-tcp:         yes
        do-daemonize:   yes
        num-threads:    4

        outgoing-range: 512
        num-queries-per-thread: 1024

        msg-cache-size:         16m
        rrset-cache-size:       32m
        key-cache-size:         16m
        cache-max-ttl:          86400

        infra-host-ttl:         60
        infra-lame-ttl:         120

        msg-cache-slabs:        4
        rrset-cache-slabs:      4
        infra-cache-slabs:      4

        access-control: 0.0.0.0/0 refuse
        access-control: 10.0.0.1/32 allow
        access-control: 127.0.0.1/32 allow
        access-control: 192.168.0.0/20 allow
        access-control: 127.0.0.1 allow
        username:       unbound
        directory:      /var/unbound
        chroot:         /var/unbound
        pidfile:        /var/run/local_unbound.pid
        hide-version:   yes

include: /var/unbound/forward.conf
include: /var/unbound/lan-zones.conf
include: /var/unbound/control.conf
include: /var/unbound/conf.d/*.conf
```

And after start unbound tells me about needs libevent for my settings:

```
Jan 20 22:31:04 MAIN-GATE unbound: [65605:0] notice: init module 0: validator
Jan 20 22:31:04 MAIN-GATE unbound: [65605:0] notice: init module 1: iterator
Jan 20 22:33:00 MAIN-GATE unbound: [65693:0] notice: init module 0: validator
Jan 20 22:33:00 MAIN-GATE unbound: [65693:0] notice: init module 1: iterator
Jan 21 00:00:01 MAIN-GATE unbound: [65693:0] notice: Restart of unbound 1.5.10.
Jan 21 00:00:01 MAIN-GATE unbound: [65693:0] warning: too many file descriptors requested. The builtinmini-event cannot handle more than 1024. Config for less fds or compile with libevent
Jan 21 00:00:01 MAIN-GATE unbound: [65693:0] warning: continuing with less udp ports: 223
Jan 21 00:00:01 MAIN-GATE unbound: [65693:0] notice: init module 0: validator
Jan 21 00:00:01 MAIN-GATE unbound: [65693:0] notice: init module 1: iterator
```

So can I resolve my problem with system unbound or I need to setup it from ports with libevent support?


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## rigoletto@ (Feb 2, 2018)

IIRC with those optimizations you did, you actually do need the version from ports with devel/libevent. The version in base is just good for light usage.

Also, THIS is a good source to start optimizing.


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