INFO Curl http://cloudstack-prp.bop.cloud.mbs:8096/?command=createNetwork&displaytext=ARTY_ITG-ADMIN&name=ARTY_ITG-ADMIN&isshared=false&networkofferingid=7&acltype=Accou
nt&zoneid=1&account=ARTY_ITG&domainid=d6ccad3b-9ec2-44d2-97d3-302c83f3f100&isdefault=true&gateway=10.200.244.129&netmask=255.255.255.192&vlan=2013&networkdomain=admin-dev.cloud.mbs&response=json
INFO  Result: { "createnetworkresponse" :  { "network" : {"id":"dd84e210-89bc-4d20-b68f-782e22d56ccc","name":"ARTY_ITG-ADMIN","displaytext":"ARTY_ITG-ADMIN","broadcastdomaintype":"V
lan","traffictype":"Guest","gateway":"10.200.244.129","netmask":"255.255.255.192","cidr":"10.200.244.128/26","zoneid":"dbb92902-c9f2-4315-b87c-067f4f9e6b0b","zonename":"CloudMBS_PRP","networkofferingid":"7","netw
orkofferingname":"DefaultSharedNetworkOffering","networkofferingdisplaytext":"Offering for Shared networks","networkofferingavailability":"Optional","issystem":false,"state":"Setup","related":"dd84e210-89bc-4d20-
b68f-782e22d56ccc","broadcasturi":"vlan://2013","dns1":"10.200.194.254","dns2":"10.200.193.1","type":"Shared","vlan":"2013","acltype":"Account","account":"ARTY_ITG","domainid":"d6ccad3b-9ec2-44d2-97d3-302c83f3f10
0","domain":"ARTY_ITG","service":[{"name":"UserData"},{"name":"Dhcp"},{"name":"Dns","capability":[{"name":"AllowDnsSuffixModification","value":"true","canchooseservicecapability":false}]}],"networkdomain":"admin-
dev.cloud.mbs","physicalnetworkid":"1d5a4f67-c84e-442a-b9b5-02d9b6939636","restartrequired":false,"specifyipranges":true,"canusefordeploy":false,"ispersistent":false,"tags":[]} }  }
INFO  [CloudOS] Curl: http://cloudstack-prp.bop.cloud.mbs:8096/?command=createVlanIpRange&account=ARTY_ITG&domainid=d6ccad3b-9ec2-44d2-97d3-302c83f3f100&networkid=dd84e210-89bc-4d20
-b68f-782e22d56ccc&gateway=10.200.244.129&netmask=255.255.255.192&startip=10.200.244.188&endip=10.200.244.190&vlan=2013&zoneid=1&forvirtualnetwork=false&response=json
INFO  Result: { "createvlaniprangeresponse" : {"errorcode":431,"cserrorcode":4350,"errortext":"The IP range with tag: 2013 already has IPs that overlap with the new range. Please sp
ecify a different start IP/end IP."} }


Cloudstack code :

if (vlanId.equals(vlan.getVlanTag()) && newVlanSubnet.equals(otherVlanSubnet)) {
    if (NetUtils.ipRangesOverlap(startIP, endIP, otherVlanStartIP, otherVlanEndIP)) {
          throw new InvalidParameterValueException("The IP range with tag: " + vlan.getVlanTag()
                  + " already has IPs that overlap with the new range. Please specify a different start IP/end IP.");
    }
    if (!vlanGateway.equals(otherVlanGateway)) {
         throw new InvalidParameterValueException("The IP range with tag: " + vlan.getVlanTag() + " has already been added with gateway " + otherVlanGateway
                   + ". Please specify a different tag.");
    }
}