> Source: [sk112578](https://support.checkpoint.com/results/sk/sk112578)

# sk112578 - DNS traffic is dropped by IPS with log "Attack Information: Bad Resource Record format, Illegal EDNS0 RR"

| Property | Value |
|----------|-------|
| Solution ID | sk112578 |
| Date Created | 2016-07-24 |
| Last Modified | 2019-02-18 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |

## Symptoms

- DNS traffic is dropped by IPS with log "*Attack Information: Bad Resource Record format, Illegal EDNS0 RR*".
*Example* :

```

Type: Log
Action: Drop
Service: domain-udp (53)
Protocol: udp
Attack Type: Non Compliant DNS
Attack Information: Bad Resource Record format, Illegal EDNS0 RR
Product: IPS Software Blade
Protection ID: DnsProtocolEnforcement
Protection Name: Non Compliant DNS
Protection Type: Protocol Anomaly DNS
```

## Cause

IPS drops DNS packets whose "Z" field is not null (in the OPT Record TTL field, refer to [RFC 6891](https://tools.ietf.org/html/rfc6891#section-6.1.4)).

## Solution

This solution requires authentication. Please log in to view the full solution.

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