centos（linux）python-scapy模块中graph的使用：报错

环境：centos 7.3 python:3.6

from scapy.all import traceroute

target = ["114.114.114.114"]
dport = [80]
res,unans = traceroute(target,dport=dport,retry=-2,maxttl=5)

之后报错：

Traceback (most recent call last):
  File "scapy_simple_1.py", line 14, in <module>
    res.graph(target="> test.svg")  
  File "/usr/lib/python2.7/site-packages/scapy-2.4.0-py2.7.egg/scapy/layers/inet.py", line 1487, in graph
    self.make_graph(ASres,padding)
  File "/usr/lib/python2.7/site-packages/scapy-2.4.0-py2.7.egg/scapy/layers/inet.py", line 1396, in make_graph
    ASNlist = ASres.resolve(*ASN_query_list)
  File "/usr/lib/python2.7/site-packages/scapy-2.4.0-py2.7.egg/scapy/as_resolvers.py", line 128, in resolve
    raise RuntimeError("Could not contact whois providers....")
RuntimeError: Could not contact whois providers....