Syslog can cann't capture dell network devices which end up with 0x00

I am using LS 2.1 syslog to capture network devices' syslog . My input configure is as below :

input {
syslog {
port => 514
type => "netsyslog"
#codec => plain { charset => "UTF-8" }
# codec => rubydebug
}
}

I can capture cisco, H3's network devices' syslog. but failed to capture Dell network devices's syslog. I used tcpdump to capture the data, and and the difference is that Dell network devices' syslog end up with 0x00, such as below
192.168.24.170.514 > 192.168.7.225.514: [udp sum ok] SYSLOG, length: 173
Facility local7 (23), Severity debug (7)
Msg: Dec 3 10:05:42 JJ-2F-SW-D2048-1-7 PORT_ML[dtlAddrTask]: pml_api.c(1710) 104771 %% pmlUnknownAddrCallBack Gi7/0/11 8C:89:A5:E2:E5:51 23 static count 0 dynamic count 1\0x00
0x0000: 3c31 3931 3e20 4465 6320 2033 2031 303a
0x0010: 3035 3a34 3220 4a4a 2d32 462d 5357 2d44
0x0020: 3230 3438 2d31 2d37 2050 4f52 545f 4d4c
0x0030: 5b64 746c 4164 6472 5461 736b 5d3a 2070
0x0040: 6d6c 5f61 7069 2e63 2831 3731 3029 2031
0x0050: 3034 3737 3120 2525 2070 6d6c 556e 6b6e
0x0060: 6f77 6e41 6464 7243 616c 6c42 6163 6b20
0x0070: 4769 372f 302f 3131 2038 433a 3839 3a41
0x0080: 353a 4532 3a45 353a 3531 2032 3320 7374
0x0090: 6174 6963 2063 6f75 6e74 2030 2064 796e
0x00a0: 616d 6963 2063 6f75 6e74 2031 00

How can I fix this issue.

The problem is fixed. It was dropped by Firewall. Dell network devices send syslog via port 514, which is lower then 1024, that is forbittedn by our FW.